Hey, one of the paper authors here, this has been a serious problem in the past (and present), but is definitely improving. For example, intel’s docs state that

Hey, one of the paper authors here, this has been a serious problem in the past (and present), but is definitely improving. For example, intel’s docs state that cmove is constant-time on recent hardware. ARM’s DIT (data-independent timing) [1] extension provides hardware-level guarantees and intel has extensive docs on how to use their chips for constant-time coding [2] [1]: https://developer.arm.com/documentation/ddi0601/2020-12/AArch64-Registers/DIT--Data-Independent-Timing https://developer.arm.com/documentation/ddi0601/2020-12/AArc... [2]: https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/best-practices/data-operand-independent-timing-isa-guidance.html https://www.intel.com/content/www/us/en/developer/articles/t...