Good explanation of when and why to use HMAC

Last Modified: Fri, 30 Nov 2012 18:40:20 +0000 ; Created: Thu, 15 Nov 2012 21:09:22 +0000

http://benlog.com/articles/2008/06/19/dont-hash-secrets/

Good explanation of how hashing functions should be used for MAC and HMAC. Especially good point about digital signatures.