IPWorks Encrypt 2022 Java Edition
Version 22.0 [Build 8369]

ECC Class

Properties   Methods   Events   Config Settings   Errors  

The ECC (Elliptic Curve Cryptography) class implements ECDSA, EdDSA, ECDH, and ECIES operations.

Syntax

ipworksencrypt.Ecc

Remarks

The ECC (Elliptic Curve Cryptography) class implements ECDSA (Elliptic Curve Digital Signature Algorithm), EdDSA (Edwards-curve Digital Signature Algorithm), and ECDH (Elliptic Curve Diffie Hellman), and ECIES (Elliptic Curve Integrated Encryption Scheme) operations. The class supports the following common operations:

  • CreateKey allows key creation for secp256r1, secp384r1, secp521r1, x25519, x448, ed25519, and ed448 keys.
  • ComputeSecret computes a shared secret between two parties using a public and private key (ECDH).
  • Sign and Verify provides a way to digitally sign data and verify signatures (ECDSA and EdDSA).
  • Encrypt and Decrypt encrypt and decrypt data using a public and private key (ECIES).

The class is very flexible and offers many properties and configuration settings to configure the class. The sections below detail the use of the class for each of the major operations listed above.

Key Creation and Management

CreateKey creates a new public and private key.

When this method is called Key is populated with the generated key. The PublicKey and PrivateKey field hold the PEM formatted public and private key for ease of use. This is helpful for storing or transporting keys more easily.

The KeyAlgorithm parameter specifies the algorithm for which the key is intended to be used. Possible values are:

KeyAlgorithmSupported Operations
secp256r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
secp384r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
secp521r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
x25519ECDH (ComputeSecret)
x448ECDH (ComputeSecret)
ed25519EdDSA (Sign and VerifySignature)
ed448EdDSA (Sign and VerifySignature)
eaSecp160k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp192k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp224k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp256k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)

NIST Curve Notes

Keys for use with the secp256r1, secp384r1, and secp521r1 curves are made up of a number of individual parameters.

The public key consists of the following parameters:

The private key consists of one value:

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

Create Key Example (secp256r1 - PEM)

//Create a key using secp256r1 Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (secp256r1 - Raw Key Params)

//Create a key using secp256r1 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" byte[] K = ecc.Key.KB; //Private key param byte[] Rx = ecc.Key.RxB; //Public key param byte[] Ry = ecc.Key.RyB; //Public key param //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaSecp256r1; //This MUST be set manually when using key params directly ecc.Key.KB = K; ecc.Key.RxB = Rx; ecc.Key.RyB = Ry; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (ed25519 - PEM)

//Create a key using ed25519 Ecc ecc = new Ecc(); ecc.CreateKey("ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Create Key Example (ed25519 - Raw Key Params)

//Create a key using ed25519 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" byte[] XPk = ecc.Key.XPkB; //Public key data byte[] XSk = ecc.Key.XSkB; //Secret key data //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaEd25519; //This MUST be set manually when using key params directly ecc.Key.XPkB = XPk; ecc.Key.XSkB = XSk; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Compute Secret (ECDH)

This method computes a shared secret using Elliptic Curve Diffie Hellman (ECDH).

When this method is called the class will use the public key specified by RecipientKey and the private key specified by Key to compute a shared secret, or secret agreement. The ComputeSecretKDF property specifies the Hash or HMAC algorithm that is applied to the raw secret. The resulting value is held by SharedSecret. The following properties are applicable when calling this method:

See ComputeSecretKDF for details on advanced settings that may be applicable for the chosen algorithm.

Keys created with the ed25519 and ed448 algorithms are not supported when calling this method.

Compute Secret Example

//Create a key for Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("x25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Create a key for Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("x25519"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Note: the public keys must be exchanged between parties by some mechanism //Create the shared secret on Party 1 ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; //Private key of this party ecc1.RecipientKey.PublicKey = ecc2_pub; //Public key of other party ecc1.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc1.ComputeSecret(); Console.WriteLine(ecc1.SharedSecret); //Create the shared secret on Party 2 ecc2.Reset(); ecc2.Key.PrivateKey = ecc2_priv; //Private key of this party ecc2.RecipientKey.PublicKey = ecc1_pub; //Public key of other party ecc2.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc2.ComputeSecret(); Console.WriteLine(ecc2.SharedSecret); //This will match the shared secret created by ecc1.

Signing (ECDSA and EdDSA)

Sign will create a hash signature using ECDSA or EdDSA. The class will use the key specified by Key to has the input data and sign the resulting hash.

Key must contain a private key created with a valid ECDSA or EdDSA algorithm. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for signing are:

  • secp256r1
  • secp384r1
  • secp521r1
  • ed25519
  • ed448

See CreateKey for details about key creation and algorithms.

When this method is called data will be read from the stream set by SetInputStream, InputFile, or InputMessage.

The hash to be signed will be computed using the specified HashAlgorithm. The computed hash is stored in the HashValue property. The signed hash is stored in the HashSignature property.

To sign as hash without first computing it set HashValue to a previously computed hash for the input data. Note: HashValue is not applicable when signing with a PureEdDSA algorithm such as "ed25519" or "ed448".

The Progress event will fire with updates for the hash computation progress only. The hash signature creation process is quick and does not require progress updates.

After calling Sign the public key must be sent to the recipient along with HashSignature and original input data so the other party may perform signature verification.

The following properties are applicable when calling this method:

The following properties are populated after calling this method:

EdDSA Notes

When the Algorithm is ed25519 or ed448 the following additional parameters are applicable:

EdDSA keys can be used with a PureEdDSA algorithm (ed25519/ed448) or as HashEdDSA (ed25519ph, ed448ph) algorithm. This is controlled by the HashEdDSA property. By default the class uses the PureEdDSA algorithm.

The PureEdDSA algorithm requires two passes over the input data but provides collision resilience. The collision resilience of PureEdDSA means even if it is feasible to compute collisions for the hash function, the algorithm is still secure. When using PureEdDSA HashValue is not applicable.

When using a HashEdDSA algorithm the input is pre-hashed and supports a single pass over the data during the signing operation. To enable HashEdDSA set HashEdDSA to True.

To specify context data when using ed25519 or ed448 set EdDSAContext.

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Verifying (ECDSA and EdDSA)

VerifySignature will verify a hash signature and return True if successful or False otherwise.

Before calling this method specify the input file by setting SetInputStream, InputFile, or InputMessage.

A public key and the hash signature are required to perform the signature verification. Specify the public key in SignerKey. Specify the hash signature in HashSignature.

When this method is called the class will compute the hash for the specified file and populate HashValue. It will verify the signature using the specified SignerKey and HashSignature.

To verify the hash signature without first computing the hash simply specify HashValue before calling this method. Note: HashValue is not applicable when the message was signed with a PureEdDSA algorithm such as ed25519 or ed448.

The Progress event will fire with updates for the hash computation progress only. The hash signature verification process is quick and does not require progress updates.

The following properties are applicable when calling this method:

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Encrypting (ECIES)

Encrypt encrypts the specified data with the ECDSA public key specified in RecipientKey.

Encryption is performed using ECIES which requires an ECDSA key. RecipientKey must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

  • secp256r1
  • secp384r2
  • secp521r1

See CreateKey for details about key creation and algorithms.

When this method is called the class will encrypt the specified data using ECIES and the encrypted data will be output. To hex encode the output set UseHex to True.

The following properties are applicable when calling this method:

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Decrypting (ECIES)

Decrypt decrypts the specified data with the ECDSA private key specified in Key.

Decryption is performed using ECIES which requires an ECDSA key. Key must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

  • secp256r1
  • secp384r2
  • secp521r1

See CreateKey for details about key creation and algorithms.

When this method is called the class will decrypt the specified data using ECIES and the decrypted data will be output. If the input data was originally hex encoded, set UseHex to True.

The following properties are applicable when calling this method:

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Property List


The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

ComputeSecretKDFThe key derivation function.
EncryptionAlgorithmThe encryption algorithm to use.
HashAlgorithmThe hash algorithm used for hash computation.
HashEdDSAWhether to use HashEdDSA when signing with an ed25519 or ed448 key.
HashSignatureThe hash signature.
HashValueThe hash value of the data.
HMACAlgorithmThe HMAC algorithm to use during encryption.
InputFileThe file to process.
InputMessageThe message to process.
IVThe initialization vector (IV) used when encrypting.
KDFThe key derivation function used during encryption and decryption.
KDFHashAlgorithmThe KDF hash algorithm to use when encrypting and decrypting.
KeyThe ECC key.
OutputFileThe output file when encrypting or decrypting.
OutputMessageThe output message when encrypting or decrypting.
OverwriteIndicates whether or not the class should overwrite files.
RecipientKeyThe public key used to compute the shared secret.
SharedSecretThe computed shared secret.
SignerKeyThe public key used to verify the signature.
UseHexWhether binary values are hex encoded.

Method List


The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

ComputeSecretComputes a shared secret.
ConfigSets or retrieves a configuration setting.
CreateKeyCreates a new key.
DecryptDecrypted the specified data.
EncryptEncrypts the specified data.
ResetResets the class.
SetInputStreamSets the stream from which the class will read data to encrypt or decrypt.
SetOutputStreamSets the stream to which the class will write encrypted or decrypted data.
SignCreates a hash signature using ECDSA or EdDSA.
VerifySignatureVerifies the signature for the specified data.

Event List


The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

ErrorInformation about errors during data delivery.
ProgressFired as progress is made.

Config Settings


The following is a list of config settings for the class with short descriptions. Click on the links for further details.

AppendSecretAn optional string to append to the secret agreement.
CNGECDHKeyThe CNG ECDH key.
CNGECDSAKeyThe CNG ECDSA key.
ConcatAlgorithmIdSpecifies the AlgorithmId subfield of the OtherInfo field.
ConcatHashAlgorithmThe hash algorithm to use when ComputeSecretKDF is Concat.
ConcatPartyUInfoSpecifies the PartyUInfo subfield of the OtherInfo field.
ConcatPartyVInfoSpecifies the PartyVInfo subfield of the OtherInfo field.
ConcatSuppPrivInfoSpecifies the SuppPrivInfo subfield of the OtherInfo field.
ConcatSuppPubInfoSpecifies the SuppPubInfo subfield of the OtherInfo field.
ECDSASignatureFormatThe format of the HashSignature when using ECDSA keys.
EdDSAContextA hex encoded string holding the bytes of the context when signing or verifying with ed25519ctx.
EncryptionKeySizeThe encryption key size.
HMACKeyA key to use when generating a Hash-based Message Authentication Code (HMAC).
HMACKeySizeSpecifies the HMAC key size to be used during encryption.
HMACOptionalInfoOptional data to be used during encryption and decryption during the HMAC step.
KDFOptionalInfoOptional data to be used during encryption and decryption during the key derivation step.
PrependSecretAn optional string to prepend to the secret agreement.
StrictKeyValidationWhether to validate provided public keys based on private keys.
TLSLabelThe TLS PRF label.
TLSSeedThe TLS PRF Seed.
BuildInfoInformation about the product's build.
GUIAvailableTells the class whether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
UseDaemonThreadsWhether threads created by the class are daemon threads.
UseInternalSecurityAPITells the class whether or not to use the system security libraries or an internal implementation.

ComputeSecretKDF Property (ECC Class)

The key derivation function.

Syntax


public int getComputeSecretKDF();


public void setComputeSecretKDF(int computeSecretKDF);


Enumerated values:
  public final static int ekdSHA1 = 0;
  public final static int ekdSHA256 = 1;
  public final static int ekdSHA384 = 2;
  public final static int ekdSHA512 = 3;
  public final static int ekdMD2 = 4;
  public final static int ekdMD4 = 5;
  public final static int ekdMD5 = 6;
  public final static int ekdHMACSHA1 = 7;
  public final static int ekdHMACSHA256 = 8;
  public final static int ekdHMACSHA384 = 9;
  public final static int ekdHMACSHA512 = 10;
  public final static int ekdHMACMD5 = 11;
  public final static int ekdTLS = 12;
  public final static int ekdConcat = 13;

Default Value

1

Remarks

This property specifies the key derivation function (KDF) and algorithm to use when calling ComputeSecret.

Possible values are:

0 (ekdSHA1) SHA-1
1 (ekdSHA256 - default) SHA-256
2 (ekdSHA384) SHA-384
3 (ekdSHA512) SHA-512
4 (ekdMD2) MD2
5 (ekdMD4) MD4
6 (ekdMD5) MD5
7 (ekdHMACSHA1) HMAC-SHA1
8 (ekdHMACSHA256) HMAC-SHA256
9 (ekdHMACSHA384) HMAC-SHA384
10 (ekdHMACSHA512) HMAC-SHA512
11 (ekdHMACMD5) HMAC-MD5
12 (ekdTLS) TLS
13 (ekdConcat) Concat

HMAC Notes

If an HMAC algorithm is selected HMACKey may optionally be set to specify the key.

TLS Notes

When set to TLS, TLSSeed and TLSLabel are required. In addition PrependSecret and AppendSecret are not applicable.

Concat Notes

If Concat is selected the following configuration settings are applicable:

EncryptionAlgorithm Property (ECC Class)

The encryption algorithm to use.

Syntax


public int getEncryptionAlgorithm();


public void setEncryptionAlgorithm(int encryptionAlgorithm);


Enumerated values:
  public final static int iesAES = 0;
  public final static int iesTripleDES = 1;
  public final static int iesXOR = 2;

Default Value

0

Remarks

This setting specifies the encryption algorithm to use when Encrypt is called. This must also be set before calling Decrypt to match the algorithm used during the initial encryption.

Possible values are:

  • 0 (iesAES - default)
  • 1 (iesTripleDES)
  • 2 (iesXOR)

AES Notes

When EncryptionAlgorithm is set to iesAES AES CBC with a default key size of 256 bits is used. To specify a different key size set EncryptionKeySize.

HashAlgorithm Property (ECC Class)

The hash algorithm used for hash computation.

Syntax


public int getHashAlgorithm();


public void setHashAlgorithm(int hashAlgorithm);


Enumerated values:
  public final static int ehaSHA1 = 0;
  public final static int ehaSHA224 = 1;
  public final static int ehaSHA256 = 2;
  public final static int ehaSHA384 = 3;
  public final static int ehaSHA512 = 4;
  public final static int ehaMD2 = 5;
  public final static int ehaMD4 = 6;
  public final static int ehaMD5 = 7;
  public final static int ehaMD5SHA1 = 8;
  public final static int ehaRIPEMD160 = 9;

Default Value

2

Remarks

This property specifies the hash algorithm used for hash computation. This is only applicable when calling Sign or VerifySignature and Algorithm specifies a ECDSA key (secp256r1, secp384r1, or secp521r1. Possible values are:

0 (ehaSHA1) SHA-1
1 (ehaSHA224) SHA-224
2 (ehaSHA256 - default) SHA-256
3 (ehaSHA384) SHA-384
4 (ehaSHA512) SHA-512
5 (ehaMD2) MD2
6 (ehaMD4) MD4
7 (ehaMD5) MD5
8 (ehaMD5SHA1) MD5SHA-1
9 (ehaRIPEMD160) RIPEMD-160

When Algorithm specified an EdDSA key this setting is not applicable as the hash algorithm is defined by the specification as SHA-512 for ed25519 and SHAKE-256 for ed448.

HashEdDSA Property (ECC Class)

Whether to use HashEdDSA when signing with an ed25519 or ed448 key.

Syntax


public boolean isHashEdDSA();


public void setHashEdDSA(boolean hashEdDSA);

Default Value

False

Remarks

This setting specifies whether to use the HashEdDSA algorithm when signing and verifying with ed25519 or ed448 keys.

If set to True the class will use the HashEdDSA algorithm (ed25519ph or ed448ph) when signing and verifying. When using a HashEdDSA algorithm the input is pre-hashed and supports a single pass over the data during the signing operation.

If set to False (Default) the class will use the PureEdDSA algorithm (ed25519 or ed448) when signing. The PureEdDSA requires two passes over the input data but provides collision resilience. The collision resilience of PureEdDSA means even if it is feasible to compute collisions for the hash function, the algorithm is still secure.

This property is only applicable when calling Sign and Algorithm is set to ed25519 or ed448.

If this property is set before calling Sign it must be set before calling VerifySignature.

HashSignature Property (ECC Class)

The hash signature.

Syntax


public byte[] getHashSignature();


public void setHashSignature(byte[] hashSignature);

Default Value

""

Remarks

This property holds the computed hash signature. This is populated after calling Sign. This must be set before calling VerifySignature.

HashValue Property (ECC Class)

The hash value of the data.

Syntax


public byte[] getHashValue();


public void setHashValue(byte[] hashValue);

Default Value

""

Remarks

This property holds the computed hash value for the specified data. This is populated when calling Sign or VerifySignature when an input file is specified by setting SetInputStream, InputFile, or InputMessage.

Pre-existing hash values may be set to this property before calling Sign or VerifySignature. If you know the hash value prior to using the class you may specify the pre-computed hash value here.

This setting is not applicable to PureEdDSA algorithms. If Algorithm is ed25519 or ed448 and HashEdDSA is False (default) the PureEdDSA algorithm is use and HashValue is not applicable.

Hash Notes

The class will determine whether or not to recompute the hash based on the properties that are set. If a file is specified by SetInputStream, InputFile, or InputMessage the hash will be recomputed when calling Sign or VerifySignature. If the HashValue property is set the class will only sign the hash or verify the hash signature. Setting SetInputStream, InputFile, or InputMessage clears the HashValue property. Setting the HashValue property clears the input file selection.

HMACAlgorithm Property (ECC Class)

The HMAC algorithm to use during encryption.

Syntax


public int getHMACAlgorithm();


public void setHMACAlgorithm(int HMACAlgorithm);


Enumerated values:
  public final static int iesHMACSHA1 = 0;
  public final static int iesHMACSHA224 = 1;
  public final static int iesHMACSHA256 = 2;
  public final static int iesHMACSHA384 = 3;
  public final static int iesHMACSHA512 = 4;
  public final static int iesHMACRIPEMD160 = 5;

Default Value

2

Remarks

This property specifies the HMAC algorithm to use when encrypting. The HMAC algorithm is used when Encrypt and Decrypt are called to protect and verify data. Possible values are:

  • 0 (iesHMACSHA1)
  • 1 (iesHMACSHA224)
  • 2 (iesHMACSHA256 - Default)
  • 3 (iesHMACSHA384)
  • 4 (iesHMACSHA512)
  • 5 (iesHMACRIPEMD160)

This property is only applicable when calling Encrypt or Decrypt.

InputFile Property (ECC Class)

The file to process.

Syntax


public String getInputFile();


public void setInputFile(String inputFile);

Default Value

""

Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

InputMessage Property (ECC Class)

The message to process.

Syntax


public byte[] getInputMessage();


public void setInputMessage(byte[] inputMessage);

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

IV Property (ECC Class)

The initialization vector (IV) used when encrypting.

Syntax


public byte[] getIV();


public void setIV(byte[] IV);

Default Value

""

Remarks

This property optionally specifies an IV to be used when calling Encrypt or Decrypt. If specified the IV is used by EncryptionAlgorithm during encryption.

If not specified the class will create an IV filled with null bytes (zeros). Since the encryption key is only used once the use of null bytes in the IV is considered acceptable and is a standard practice.

The length of the IV should be as follows:

EncryptionAlgorithmIV Length (in bytes)
AES16
3DES8

This setting is not applicable when EncryptionAlgorithm is set to XOR.

KDF Property (ECC Class)

The key derivation function used during encryption and decryption.

Syntax


public String getKDF();


public void setKDF(String KDF);

Default Value

"KDF2"

Remarks

This property specifies the key derivation function (KDF) to use when encrypting and decrypting. Possible values are:

  • "KDF1"
  • "KDF2" (Default)
The KDFHashAlgorithm specifies the hash algorithm used in conjunction with the specified KDF.

This property is only applicable when calling Encrypt or Decrypt.

KDFHashAlgorithm Property (ECC Class)

The KDF hash algorithm to use when encrypting and decrypting.

Syntax


public int getKDFHashAlgorithm();


public void setKDFHashAlgorithm(int KDFHashAlgorithm);


Enumerated values:
  public final static int iesSHA1 = 0;
  public final static int iesSHA224 = 1;
  public final static int iesSHA256 = 2;
  public final static int iesSHA384 = 3;
  public final static int iesSHA512 = 4;

Default Value

2

Remarks

This property specifies the hash algorithm to use in when deriving a key using the specified KDF. Possible values are:

  • 0 (iesSHA1)
  • 1 (iesSHA224)
  • 2 (iesSHA256)
  • 3 (iesSHA384)
  • 4 (iesSHA512)

This property is only applicable when calling Encrypt or Decrypt.

Key Property (ECC Class)

The ECC key.

Syntax


public ECCKey getKey();


public void setKey(ECCKey key);

Remarks

This property specifies the ECC private key. This property must be set before calling Sign or ComputeSecret.

NIST Curve Notes

Keys for use with the secp256r1, secp384r1, and secp521r1 curves are made up of a number of individual parameters.

The public key consists of the following parameters:

The private key consists of one value:

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

OutputFile Property (ECC Class)

The output file when encrypting or decrypting.

Syntax


public String getOutputFile();


public void setOutputFile(String outputFile);

Default Value

""

Remarks

This property specifies the file to which the output will be written when Encrypt or Decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

OutputMessage Property (ECC Class)

The output message when encrypting or decrypting.

Syntax


public byte[] getOutputMessage();


Default Value

""

Remarks

This property will be populated with the output after calling Encrypt or Decrypt if OutputFile and SetOutputStream are not set.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

This property is read-only and not available at design time.

Overwrite Property (ECC Class)

Indicates whether or not the class should overwrite files.

Syntax


public boolean isOverwrite();


public void setOverwrite(boolean overwrite);

Default Value

False

Remarks

This property indicates whether or not the class will overwrite OutputFile. If Overwrite is False, an error will be thrown whenever OutputFile exists before an operation. The default value is False.

RecipientKey Property (ECC Class)

The public key used to compute the shared secret.

Syntax


public ECCKey getRecipientKey();


public void setRecipientKey(ECCKey recipientKey);

Remarks

This property specifies the public key used to compute the shared secret. This must be set before calling ComputeSecret.

SharedSecret Property (ECC Class)

The computed shared secret.

Syntax


public byte[] getSharedSecret();


Default Value

""

Remarks

This property holds the shared secret computed by ComputeSecret.

This property is read-only.

SignerKey Property (ECC Class)

The public key used to verify the signature.

Syntax


public ECCKey getSignerKey();


public void setSignerKey(ECCKey signerKey);

Remarks

This property specifies the public key used to verify the signature. This public key corresponds to the private key used when creating the signature. This must be set before calling VerifySignature.

UseHex Property (ECC Class)

Whether binary values are hex encoded.

Syntax


public boolean isUseHex();


public void setUseHex(boolean useHex);

Default Value

False

Remarks

This setting specifies whether various calculated values are hex encoded. If set to False (Default) all data is provided as-is with no encoding.

If set to True certain properties are hex encoded when populated for ease of display, transport, and storage.

Compute Secret Notes

This property specifies whether SharedSecret is hex encoded when ComputeSecret is called.

Sign and Verify Notes

This property specifies whether HashValue and HashSignature are hex encoded.

If set to True, when Sign is called the class will compute the hash for the specified file and populate HashValue with the hex encoded hash value. It will then create the hash signature and populate HashSignature with the hex encoded hash signature value. If HashValue is specified directly it must be a hex encoded value.

If set to True, when VerifySignature is called the class will compute the hash value for the specified file and populate HashValue with the hex encoded hash value. It will then hex decode HashSignature and verify the signature. HashSignature must hold a hex encoded value. If HashValue is specified directly it must be a hex encoded value.

Encrypt and Decrypt Notes

If set to True, when Encrypt is called the class will perform the encryption as normal and then hex encode the output. OutputMessage or OutputFile will hold hex encoded data.

If set to True, when Decrypt is called the class will expect InputMessage or InputFile to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.

ComputeSecret Method (Ecc Class)

Computes a shared secret.

Syntax

public void computeSecret();

Remarks

This method computes a shared secret using Elliptic Curve Diffie Hellman (ECDH).

When this method is called the class will use the public key specified by RecipientKey and the private key specified by Key to compute a shared secret, or secret agreement. The ComputeSecretKDF property specifies the Hash or HMAC algorithm that is applied to the raw secret. The resulting value is held by SharedSecret. The following properties are applicable when calling this method:

See ComputeSecretKDF for details on advanced settings that may be applicable for the chosen algorithm.

Keys created with the ed25519 and ed448 algorithms are not supported when calling this method.

Compute Secret Example

//Create a key for Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("x25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Create a key for Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("x25519"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Note: the public keys must be exchanged between parties by some mechanism //Create the shared secret on Party 1 ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; //Private key of this party ecc1.RecipientKey.PublicKey = ecc2_pub; //Public key of other party ecc1.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc1.ComputeSecret(); Console.WriteLine(ecc1.SharedSecret); //Create the shared secret on Party 2 ecc2.Reset(); ecc2.Key.PrivateKey = ecc2_priv; //Private key of this party ecc2.RecipientKey.PublicKey = ecc1_pub; //Public key of other party ecc2.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc2.ComputeSecret(); Console.WriteLine(ecc2.SharedSecret); //This will match the shared secret created by ecc1.

Config Method (Ecc Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

CreateKey Method (Ecc Class)

Creates a new key.

Syntax

public void createKey(String keyAlgorithm);

Remarks

CreateKey creates a new public and private key.

When this method is called Key is populated with the generated key. The PublicKey and PrivateKey field hold the PEM formatted public and private key for ease of use. This is helpful for storing or transporting keys more easily.

The KeyAlgorithm parameter specifies the algorithm for which the key is intended to be used. Possible values are:

KeyAlgorithmSupported Operations
secp256r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
secp384r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
secp521r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
x25519ECDH (ComputeSecret)
x448ECDH (ComputeSecret)
ed25519EdDSA (Sign and VerifySignature)
ed448EdDSA (Sign and VerifySignature)
eaSecp160k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp192k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp224k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp256k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)

NIST Curve Notes

Keys for use with the secp256r1, secp384r1, and secp521r1 curves are made up of a number of individual parameters.

The public key consists of the following parameters:

The private key consists of one value:

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

Create Key Example (secp256r1 - PEM)

//Create a key using secp256r1 Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (secp256r1 - Raw Key Params)

//Create a key using secp256r1 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" byte[] K = ecc.Key.KB; //Private key param byte[] Rx = ecc.Key.RxB; //Public key param byte[] Ry = ecc.Key.RyB; //Public key param //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaSecp256r1; //This MUST be set manually when using key params directly ecc.Key.KB = K; ecc.Key.RxB = Rx; ecc.Key.RyB = Ry; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (ed25519 - PEM)

//Create a key using ed25519 Ecc ecc = new Ecc(); ecc.CreateKey("ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Create Key Example (ed25519 - Raw Key Params)

//Create a key using ed25519 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" byte[] XPk = ecc.Key.XPkB; //Public key data byte[] XSk = ecc.Key.XSkB; //Secret key data //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaEd25519; //This MUST be set manually when using key params directly ecc.Key.XPkB = XPk; ecc.Key.XSkB = XSk; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Decrypt Method (Ecc Class)

Decrypted the specified data.

Syntax

public void decrypt();

Remarks

Decrypt decrypts the specified data with the ECDSA private key specified in Key.

Decryption is performed using ECIES which requires an ECDSA key. Key must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

  • secp256r1
  • secp384r2
  • secp521r1

See CreateKey for details about key creation and algorithms.

When this method is called the class will decrypt the specified data using ECIES and the decrypted data will be output. If the input data was originally hex encoded, set UseHex to True.

The following properties are applicable when calling this method:

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt Method (Ecc Class)

Encrypts the specified data.

Syntax

public void encrypt();

Remarks

Encrypt encrypts the specified data with the ECDSA public key specified in RecipientKey.

Encryption is performed using ECIES which requires an ECDSA key. RecipientKey must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

  • secp256r1
  • secp384r2
  • secp521r1

See CreateKey for details about key creation and algorithms.

When this method is called the class will encrypt the specified data using ECIES and the encrypted data will be output. To hex encode the output set UseHex to True.

The following properties are applicable when calling this method:

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Reset Method (Ecc Class)

Resets the class.

Syntax

public void reset();

Remarks

When called, the class will reset all of its properties to their default values.

SetInputStream Method (Ecc Class)

Sets the stream from which the class will read data to encrypt or decrypt.

Syntax

public void setInputStream(java.io.InputStream inputStream);

Remarks

This method sets the stream from which the class will read data to encrypt or decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

SetOutputStream Method (Ecc Class)

Sets the stream to which the class will write encrypted or decrypted data.

Syntax

public void setOutputStream(java.io.OutputStream outputStream);

Remarks

This method sets the stream to which the class will write encrypted or decrypted data.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

  • SetOutputStream
  • OutputFile
  • OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Sign Method (Ecc Class)

Creates a hash signature using ECDSA or EdDSA.

Syntax

public void sign();

Remarks

Sign will create a hash signature using ECDSA or EdDSA. The class will use the key specified by Key to has the input data and sign the resulting hash.

Key must contain a private key created with a valid ECDSA or EdDSA algorithm. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for signing are:

  • secp256r1
  • secp384r1
  • secp521r1
  • ed25519
  • ed448

See CreateKey for details about key creation and algorithms.

When this method is called data will be read from the stream set by SetInputStream, InputFile, or InputMessage.

The hash to be signed will be computed using the specified HashAlgorithm. The computed hash is stored in the HashValue property. The signed hash is stored in the HashSignature property.

To sign as hash without first computing it set HashValue to a previously computed hash for the input data. Note: HashValue is not applicable when signing with a PureEdDSA algorithm such as "ed25519" or "ed448".

The Progress event will fire with updates for the hash computation progress only. The hash signature creation process is quick and does not require progress updates.

After calling Sign the public key must be sent to the recipient along with HashSignature and original input data so the other party may perform signature verification.

The following properties are applicable when calling this method:

The following properties are populated after calling this method:

EdDSA Notes

When the Algorithm is ed25519 or ed448 the following additional parameters are applicable:

EdDSA keys can be used with a PureEdDSA algorithm (ed25519/ed448) or as HashEdDSA (ed25519ph, ed448ph) algorithm. This is controlled by the HashEdDSA property. By default the class uses the PureEdDSA algorithm.

The PureEdDSA algorithm requires two passes over the input data but provides collision resilience. The collision resilience of PureEdDSA means even if it is feasible to compute collisions for the hash function, the algorithm is still secure. When using PureEdDSA HashValue is not applicable.

When using a HashEdDSA algorithm the input is pre-hashed and supports a single pass over the data during the signing operation. To enable HashEdDSA set HashEdDSA to True.

To specify context data when using ed25519 or ed448 set EdDSAContext.

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

VerifySignature Method (Ecc Class)

Verifies the signature for the specified data.

Syntax

public boolean verifySignature();

Remarks

VerifySignature will verify a hash signature and return True if successful or False otherwise.

Before calling this method specify the input file by setting SetInputStream, InputFile, or InputMessage.

A public key and the hash signature are required to perform the signature verification. Specify the public key in SignerKey. Specify the hash signature in HashSignature.

When this method is called the class will compute the hash for the specified file and populate HashValue. It will verify the signature using the specified SignerKey and HashSignature.

To verify the hash signature without first computing the hash simply specify HashValue before calling this method. Note: HashValue is not applicable when the message was signed with a PureEdDSA algorithm such as ed25519 or ed448.

The Progress event will fire with updates for the hash computation progress only. The hash signature verification process is quick and does not require progress updates.

The following properties are applicable when calling this method:

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Error Event (Ecc Class)

Information about errors during data delivery.

Syntax

public class DefaultEccEventListener implements EccEventListener {
  ...
  public void error(EccErrorEvent e) {}
  ...
}

public class EccErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class throws an exception.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Progress Event (Ecc Class)

Fired as progress is made.

Syntax

public class DefaultEccEventListener implements EccEventListener {
  ...
  public void progress(EccProgressEvent e) {}
  ...
}

public class EccProgressEvent {
  public long bytesProcessed;
  public int percentProcessed;
}

Remarks

This event is fired automatically as data is processed by the class.

The PercentProcessed parameter indicates the current status of the operation.

The BytesProcessed parameter holds the total number of bytes processed so far.

ECCKey Type

Contains the parameters for the ECC algorithm.

Remarks

This type is made up of fields that represent the private and public key parameters used by the ECC operations. The PrivateKey and PublicKey parameters hold a PEM formatted value for easy transport and storage of keys.

NIST Curve Notes

Keys for use with the secp256r1, secp384r1, and secp521r1 curves are made up of a number of individual parameters.

The public key consists of the following parameters:

The private key consists of one value:

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

Fields

Algorithm
int

This field holds the algorithm associated with the key. Possible values are:

  • 0 (eaSecp256r1)
  • 1 (eaSecp384r1)
  • 2 (eaSecp521r1)
  • 3 (eaEd25519)
  • 4 (eaEd448)
  • 5 (eaX25519)
  • 6 (eaX448)
  • 7 (eaSecp160k1)
  • 8 (eaSecp192k1)
  • 9 (eaSecp224k1)
  • 10 (eaSecp256k1)

When assigning a key using the PEM formatted PrivateKey and PublicKey the Algorithm field will be automatically updated with the key algorithm.

When assigning a key using the raw key parameters (K, Rx, and Ry for NIST or XPk, and XSk for Curve25519/Curve448) the Algorithm field must be set manually to the key algorithm.

The following table summarizes the supported operations for keys created with each algorithm:

KeyAlgorithmSupported Operations
secp256r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
secp384r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
secp521r1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
x25519ECDH (ComputeSecret)
x448ECDH (ComputeSecret)
ed25519EdDSA (Sign and VerifySignature)
ed448EdDSA (Sign and VerifySignature)
eaSecp160k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp192k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp224k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)
eaSecp256k1ECDH/ECIES/ECDSA (ComputeSecret, Encrypt, Decrypt, Sign, and VerifySignature)

K
String

Represent the private key (K) parameter.

Note: This value is only applicable when using a NIST curve.

KB
byte[]

Represent the private key (K) parameter.

Note: This value is only applicable when using a NIST curve.

PrivateKey
String

This field is a PEM formatted private key. The purpose of this field is to allow easier management of the private key parameters by using only a single value.

PublicKey
String

This field is a PEM formatted public key. The purpose of this field is to allow easier management of the public key parameters by using only a single value.

Rx
String

Represents the public key's Rx parameter.

Note: This value is only applicable when using a NIST curve.

RxB
byte[]

Represents the public key's Rx parameter.

Note: This value is only applicable when using a NIST curve.

Ry
String

Represents the public key's Ry parameter.

Note: This value is only applicable when using a NIST curve.

RyB
byte[]

Represents the public key's Ry parameter.

Note: This value is only applicable when using a NIST curve.

XPk
String

Holds the public key data.

Note: This value is only applicable when using Curve25519 or Curve448.

XPkB
byte[]

Holds the public key data.

Note: This value is only applicable when using Curve25519 or Curve448.

XSk
String

Holds the private key data.

Note: This value is only applicable when using Curve25519 or Curve448.

XSkB
byte[]

Holds the private key data.

Note: This value is only applicable when using Curve25519 or Curve448.

Constructors

public ECCKey();

The default constructor creates a new ECCKey instance but does not assign a public or private key.

public ECCKey( rx,  ry,  algorithm);

The public key constructor assigns an existing public key.

public ECCKey( K,  rx,  ry,  algorithm);

The private key constructor assigns an existing private key.

Config Settings (Ecc Class)

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

ECC Config Settings

AppendSecret:   An optional string to append to the secret agreement.

This setting specifies an optional string to append to the secret agreement before hashing it. This is applicable when calling ComputeSecret.

Note: This is not applicable when ComputeSecretKDF is set to 12 (ekdTLS).

CNGECDHKey:   The CNG ECDH key.

This setting may be set to specify the key exported from Microsoft's CNG before calling ComputeSecret. If key data was obtained from Microsoft's CNG API it can be hex encoded and supplied here. The class will use this key when ComputeSecret is called.

CNGECDSAKey:   The CNG ECDSA key.

This setting may be set to specify the key exported from Microsoft's CNG before calling VerifySignature. If key data was obtained from Microsoft's CNG API it can be hex encoded and supplied here. The class will use this key when VerifySignature is called.

ConcatAlgorithmId:   Specifies the AlgorithmId subfield of the OtherInfo field.

This setting specifies the AlgorithmId subfield of the OtherInfo field as described in the publication "NIST SP 800-56A" section 5.8.1. The value supplied to this setting must be a hex encoded string of the subfield data.

This setting is required when ComputeSecretKDF is set to ekdConcat. This setting is only applicable when calling ComputeSecret.

ConcatHashAlgorithm:   The hash algorithm to use when ComputeSecretKDF is Concat.

This optionally specifies the hash algorithm to use when ComputeSecretKDF is set to ekdConcat. Possible values are:

  • SHA1
  • SHA224
  • SHA256 (default)
  • SHA384
  • SHA512
  • RIPEMD160
ConcatPartyUInfo:   Specifies the PartyUInfo subfield of the OtherInfo field.

This setting specifies the PatyUInfo subfield of the OtherInfo field as described in the publication "NIST SP 800-56A" section 5.8.1. The value supplied to this setting must be a hex encoded string of the subfield data.

This setting is required when ComputeSecretKDF is set to ekdConcat. This setting is only applicable when calling ComputeSecret.

ConcatPartyVInfo:   Specifies the PartyVInfo subfield of the OtherInfo field.

This setting specifies the PartyVInfo subfield of the OtherInfo field as described in the publication "NIST SP 800-56A" section 5.8.1. The value supplied to this setting must be a hex encoded string of the subfield data.

This setting is required when ComputeSecretKDF is set to ekdConcat. This setting is only applicable when calling ComputeSecret.

ConcatSuppPrivInfo:   Specifies the SuppPrivInfo subfield of the OtherInfo field.

This setting specifies the SuppPrivInfo subfield of the OtherInfo field as described in the publication "NIST SP 800-56A" section 5.8.1. The value supplied to this setting must be a hex encoded string of the subfield data.

This setting is optional when ComputeSecretKDF is set to ekdConcat. This setting is only applicable when calling ComputeSecret.

ConcatSuppPubInfo:   Specifies the SuppPubInfo subfield of the OtherInfo field.

This setting specifies the SuppPubInfo subfield of the OtherInfo field as described in the publication "NIST SP 800-56A" section 5.8.1. The value supplied to this setting must be a hex encoded string of the subfield data.

This setting is optional when ComputeSecretKDF is set to ekdConcat. This setting is only applicable when calling ComputeSecret.

ECDSASignatureFormat:   The format of the HashSignature when using ECDSA keys.

This setting specifies the format of HashSignature when signing with ECDSA keys. The way the HashSignature parameters are represented can be changed to be interoperable with other implementations. Possible values are:

  • 0 (Concatenated - default)
  • 1 (ASN)

Note: This setting is only applicable when Algorithm is set to secp256r1, secp384r1, or secp521r1.

EdDSAContext:   A hex encoded string holding the bytes of the context when signing or verifying with ed25519ctx.

This setting specifies up to 255 bytes of context data as a hex encoded string for during signing and verifying.

This setting is only applicable when Algorithm is set to ed25519 or ed448. When this setting is specified and the Algorithm is ed25519 and HashEdDSA is False the class will automatically use ed25519ctx.

If this value is specified before calling Sign, it must also be set prior to calling VerifySignature.

EncryptionKeySize:   The encryption key size.

This setting specifies the AES encryption key size in bits when EncryptionAlgorithm is set to AES. Possible values are:

  • 128
  • 192
  • 256 (default)
This setting is only applicable when calling Encrypt.
HMACKey:   A key to use when generating a Hash-based Message Authentication Code (HMAC).

This key is incorporated into the hashing process to add entropy to the resulting hash code, making the plaintext harder to guess and increasing the message security. The value supplied here must be hex encoded.

This is only applicable when calling ComputeSecret.

HMACKeySize:   Specifies the HMAC key size to be used during encryption.

This setting optionally specifies the HMAC key size to be used during encryption and decryption. If set to 0 (default) the class will automatically select the key size based on the algorithm specified in HMACAlgorithm.

This setting is only applicable when calling Encrypt or Decrypt.

HMACOptionalInfo:   Optional data to be used during encryption and decryption during the HMAC step.

This setting optionally specifies data to be used with the specified HMACAlgorithm as part of the encryption and decryption process. This is additional data known to both parties that is included while performing the HMAC operation.

The value specified in this setting must a hex string.

If specified this must be set before calling both Encrypt and Decrypt.

KDFOptionalInfo:   Optional data to be used during encryption and decryption during the key derivation step.

This setting optionally specifies data to be used with the specified KDF as part of the encryption and decryption process. This is additional data known to both parties that is included while performing key derivation.

The value specified in this setting must a hex string.

If specified this must be set before calling both Encrypt and Decrypt.

PrependSecret:   An optional string to prepend to the secret agreement.

This setting specifies an optional string to prepend to the secret agreement before hashing it. This is applicable when calling ComputeSecret.

Note: This is not applicable when ComputeSecretKDF is set to 12 (ekdTLS).

StrictKeyValidation:   Whether to validate provided public keys based on private keys.

This setting performs additional checks prior to using specified keys to validate the public key corresponds to the provided private key.

When using keys with the algorithm ed25519, ed448, X25519, or X448 the class will calculate the public key based on the provided private key and compare it to the provided public key to ensure they match.

When using keys with the algorithm secp256r1, secp384r1, or secp521r1 the class will perform calculations to verify the public key is a point on the curve. The class will also calculate the public key based on the provided private key and compare it to the provided public key to ensure they match.

The default value is False and the class will use the public and private keys as provided without any additional checks.

TLSLabel:   The TLS PRF label.

This setting specifies a string representing the PRF label. This setting is required when ComputeSecretKDF set to 12 (ekdTLS). It is only applicable when calling ComputeSecret.

TLSSeed:   The TLS PRF Seed.

This setting specifies the hex encoded TLS PRF Seed. The seed value must be 64 bytes in length before hex encoding. This setting is required when ComputeSecretKDF set to 12 (ekdTLS). It is only applicable when calling ComputeSecret.

Base Config Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

GUIAvailable:   Tells the class whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The class will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the class does not attempt to process external events.

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
UseDaemonThreads:   Whether threads created by the class are daemon threads.

If set to True (default), when the class creates a thread, the thread's Daemon property will be explicitly set to True. When set to False, the class will not set the Daemon property on the created thread. The default value is True.

UseInternalSecurityAPI:   Tells the class whether or not to use the system security libraries or an internal implementation.

By default the class will use the system security libraries to perform cryptographic functions where applicable. Setting this to true tells the class to use the internal implementation instead of using the system's security API.

Trappable Errors (Ecc Class)

ECC Errors

102   No Key specified.
104   Cannot read or write file.
111   OutputFile already exists and Overwrite is False.
120   Invalid curve.
124   HashSignature must be specified.
304   Cannot write file.
305   Cannot read file.
306   Cannot create file.

Copyright (c) 2022 /n software inc. - All rights reserved.
IPWorks Encrypt 2022 Java Edition - Version 22.0 [Build 8369]