MAC Calculator

Calculate Message Authentication Codes (MAC) using ISO 9797-1 algorithms.

⚠️ For testing and educational use only. Do not use for actual message authentication in production systems.

ISO 9797-1 MAC Calculator

Generate and verify Message Authentication Codes for payment message integrity.

This is a simplified version of the MAC calculator for troubleshooting purposes.

Algorithm

Algorithm 1 (CBC-MAC)

Algorithm 3 (Retail MAC)

Input Data

Key 1 (Hex)

Key 2 (Hex)

Understanding MAC Algorithms

What is a MAC?

A Message Authentication Code (MAC) is a cryptographic checksum that ensures message integrity and authenticity. In payment systems, MACs are used to verify that messages have not been altered during transmission and that they originate from a trusted source.

EMV Decoder tools perform all calculations client-side for maximum security.
No sensitive data is ever transmitted to our servers.