Subject: Should Linux set the new constant-time mode CPU flags?
"Intel and ARM recently published documentation that says that NO instructions are guaranteed to be constant-time [on microarchitectures after Ice Lack] with respect to their data operands, unless a "data independent timing" flag [...] is set"
So... Can we hack some blockchain using this feature?
For crypto operations, like the simplest one, comparing an input string against the known one. If we use xor to do the comparison, how on earth the time consumption will be different? (Only using xor is possibly not considered as crypto operation, but the idea is how can Intel use different amount of time for calculating the same amount of data?)
Or it's just Intel's excuse for don't blame me if your code don't work securely on newer CPUs?
