IV Property

The initialization vector (IV).

Syntax

property IV: String read get_IV write set_IV;
property IVB: TBytes read get_IVB write set_IVB;

Default Value

''

Remarks

This property specifies the initialization vector (IV). This is also referred to as the nonce. By default this property is empty and the component will automatically generate a new IV value if KeyPassword or Key is set before Encrypt or EncryptBlock is called.

The size of the IV may be either 96 bits in length (12 bytes) or 64 bits in length (8 bytes).

Compatibility Notes

A 96 bit length value is used for implementations implementing RFC 7539. A 64 bit length value may be used by implementations that follow the original draft of ChaCha. When using a 96 bit length value the maximum file size of data is 256 GB.

If another entity is performing the decryption and it is not known whether it supports 64 bit length values, choose a 96 bit length value by default. This follows the RFC and should be the most widely implemented value.

The component supports both lengths.

Note: If Key is specified but IV is not, an IV will be automatically generated. To control the length of the IV that is generated set IVLength.