Okay, I was finally able to find a direct answer to my question by studying NaCl. http://cryptojedi.org/peter/data/tenerife-20130121.pdf http://cryptojedi.org/

Okay, I was finally able to find a direct answer to my question by studying NaCl. http://cryptojedi.org/peter/data/tenerife-20130121.pdf http://cryptojedi.org/peter/data/tenerife-20130121.pdf "NaCl systematically avoids all loads from addresses that depend on secret data" "NaCl systematically avoids all branch conditions that depend on secret data" So NaCl is an implementation of AES encryption that prevents cache timing attacks. Since there are no other reasonable side channel attacks on AES, the AES key remains secure. Therefore reusing your AES key is ok provided you're using NaCl. (So you should probably be telling people they need to be using NaCl, not merely AES.) Thank you for the answers. Also, thanks for pointing me at NaCl. That's the most exciting crypto slide deck that's ever been written!