To indicate the beginning of a Cryptographic Service Message (CSM) Transaction Set and to provide both the class or type of the CSM and the cryptographic end parties to the transaction
Code specifying the Message class (MCL)
Unique designation (identity) of the cryptographic process that performs authentication or encryption on data to be interchanged, or originates a cryptographic service message
Note: X9 has a minimum length of 4 characters for the security originator; no mechanism, or registration method is provided by X9 or X12 to guarantee the uniqueness of the identifier
Unique designation (identity) of the cryptographic process that performs authentication or decryption on received data, or is the destination of a cryptographic service message
Note: X9 has a minimum length of 4 characters for the security recipient; no mechanism, or registration method is provided by X9 or X12 to guarantee the uniqueness of the identifier
