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- How secure is AES-256? 3 answers
Im trying to understand if nowadays using AES is secure or not, after reading some arguments on Schneier’s blog (to be more exact, a comment to “The NSA Is Breaking Most Encryption on the Internet”) it seems like it is not secure:
Now as the NSA GCHQ et al know very well the more efficient you make the implementation of crypto code the more side channels it has unless extreme caution is observed. One thing we do know is that optimized for speed and minimized number of gates is an almost certain guarantee of side channels no matter how clever you are. Also the NSA knew that developers would not write their own code they would simply download and use the competition candidate code.
As was pointed out and demonstration code exploited implementations of AES were subject to timing attacks that could fully leak the key across a network connection due to "cache hits" on the Intel x86 platform from base level pentiums upwards within weeks of the winning candidate being announced. Even today there are very side channel suseptable AES implementations in use in fact the majority of those implementations on the likes of routers and switches are timing channel cursed as are most application level software implementations that are more than a year or so old...
…at least not if the computer used is connected to external network.
Is this true or just based on assumptions?