AAV Decoder

The AAV (Accountholder Authentication Value) is a cryptographic value used in Mastercard's SecureCode protocol, which is part of the 3-D Secure authentication system for online card transactions.

Purpose: The AAV serves as proof that authentication was performed during an online transaction. It's generated by the issuing bank during the authentication process and is later verified during transaction authorization.

Structure: The AAV typically contains information about:

• The version of the authentication protocol used
• The source of the authentication data
• The type of message or transaction
• The method used for authentication
• The result of the authentication attempt
• Additional data that may be specific to the issuer

Security: In actual implementations, the AAV is generated using cryptographic algorithms and secret keys known only to the issuing bank. This ensures that the AAV cannot be forged by fraudsters.

Note: This decoder provides a simplified interpretation of AAV data for educational purposes. In production systems, the exact format and cryptographic validation of AAVs would follow Mastercard's specifications and security requirements.