A general rule of thumb is that any added complexity to crypto algorithms makes the attackers job easier in the end as accounting for all of the side channels b

A general rule of thumb is that any added complexity to crypto algorithms makes the attackers job easier in the end as accounting for all of the side channels becomes much harder. Timing attacks are somewhat annoying and noisy to conduct over the Internet, but you can measure the time a process takes with a resolution down to ~15ns[0]. I bet there is all sorts of cross core cache errata that leaks more time than that. [0]: https://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf https://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf