5 ms·
A bit tired with "Just use HMAC". HMAC makes you pull a hash dependency, which is not much if you do software, but can be a waste of silicon if all you want is
by brohee 9y ago
A bit tired with "Just use HMAC". HMAC makes you pull a hash dependency, which is not much if you do software, but can be a waste of silicon if all you want is a MAC. If you already spent real estate on AES, then CMAC becomes a lot more attractive...
This is the reasons it's at the core of SCP03, the smartcard world is very sensitive to transistor count...
- lvh 9y agoThe audience for this document is software engineers. It woudl be impossible to write a document that serves every audience. Unless you're also suggesting that you should AES-CMAC a password reset token? And if we're going to go there, why not PMAC? Or OMAC?
- bsder 9y ago> This is the reasons it's at the core of SCP03, the smartcard world is very sensitive to transistor count... The reason it's at the core of SCP03 is because SCP03 is ancient (2006?) and once things get affixed intro a "standard" things now move at a glacial pace. And, nowadays, fixed logic transistor count is almost irrelevant. RAM transistor count, however, is expensive and getting moreso.
- brohee 9y agoSCP03 is from 2009 actually. But its authors were likely very aware of HMAC, yet chose CMAC.