Access key value received after a MFA authentication in a previous signon.
This might be returned in the server response after a MFA authentication (i.e. MFA challenge question/answer pairs were validated by the server when the SendChallengeAnswers method in FIProfile component was called).
To prevent servers from needing to authenticate the user in each OFX request, the server may respond to a correct set of challenge answers with a OFXAccessKey on the signon response (when the SendChallengeAnswers method in FIProfile component was called).
The server determines the contents of this optional element. On each subsequent signon request, the client will send the last value of the OFXAccessKey it has received, even after the end of the current session. The server has the option to respond to any subsequent request with a 3000 error code, requiring the client to send the MFA challenge questions request again (by calling the RequestChallengeQuestions method in FIProfile component). This allows the server to determine the lifetime of the OFXAccessKey.