I’ve been tinkering with SHA-3 for a little bit, and I have some questions regarding the applicability of cache timing attacks on this particular hash function. The two sub functions that I believe are susceptible to this particular attack are THETA and CHI. I think I can prove that THETA does not run in constant time, depending on the particular method with which the algorithm is implemented, and I believe CHI does not run in constant time either. To prove that statement with CHI would require the addition of break statements in some implementations of that function. Something that I have yet to complete.
Now assuming that the attacker only has access to a static SHA-3 hash output, I doubt that any information can be gained about the input. However assuming the attacker is able to monitor the execution time of the hash function things get more interesting. Although I'm not sure how prevalent this second scenario is in real life. All that would be gained is the total execution time of all 24 rounds of THETA, but would it be possible from this value to determine the execution time of individual rounds of THETA? Or then be able to approximate inputs based on execution time?
Does anyone know of any references/articles related to SHA-3 and cache timing attacks?