Providing a way to check the integrity of information
transmitted over or stored in an unreliable medium is a prime necessity in the
world of open computing and communications. Mechanisms that provide such
integrity check based on a secret key are usually called "Message
Authentication Codes" (MACs). Typically, message authentication codes are used
between two parties that share a secret key in order to validate information
transmitted between these parties.
MACs based on cryptographic hash functions are known
as "Keyed-Hash Message Authentication Codes" (HMACs).
HMAC, as defined in RFC2104, is a mechanism for
message authentication using cryptographic hash functions. HMAC can be used with
any iterative cryptographic hash function, e.g., MD5, SHA-1, in combination with
a secret shared key. The cryptographic strength of HMAC depends on the
properties of the underlying hash function.
CHMAC Overview |
HMAC API Overview |
Useful Links | HashCalc
QuickHash Library Overview