4 ms·
Is there that much overhead in using a general block cypher to build a stream cypher?
by yarg 4y ago
Is there that much overhead in using a general block cypher to build a stream cypher?
- throwaway81523 4y agoThe issue is that for most authenticated modes, you have to run the block cipher twice in some manner, once to encrypt and once to authenticate. OCB is an exception but I don't know what its status is these days; and, iirc, it still has to do some finite field arithmetic which can be slow in software.