HMAC

HMAC (Hash-based Message Authentication Code) is a cryptographic technique used to verify both the integrity and authenticity of a message. It combines a cryptographic hash function (like SHA-256) with a secret key to produce a message authentication code, ensuring that the message has not been altered and originates from a trusted source. It is widely used in secure communication protocols, APIs, and data verification scenarios.

Also known as: Hash-based Message Authentication Code, HMAC-SHA, Keyed-Hash Message Authentication Code, Message Authentication Code, MAC

Why learn HMAC?

Developers should learn HMAC when building systems that require secure data transmission or authentication, such as API security (e.g., signing requests in REST APIs), verifying data integrity in file transfers, or implementing secure tokens in web applications. It is essential for preventing tampering and ensuring that messages are from authorized senders, making it a key component in cybersecurity and data protection.

Learning Resources

• docs: RFC 2104 - HMAC: Keyed-Hashing for Message Authentication
• tutorial: HMAC Explained - Khan Academy
• course: Cryptography I - Coursera (includes HMAC)
• tutorial: HMAC in Python - Real Python Tutorial
• docs: HMAC - Wikipedia