4 ms·
Why is this based on a symmetric problem (encoder solving the same problem as the decoder) requiring two days of crunching on a 16 core machine? Is it because
by shasta 12y ago
Why is this based on a symmetric problem (encoder solving the same problem as the decoder) requiring two days of crunching on a 16 core machine? Is it because all known asymmetric problems (factoring primes, etc.) allow large speed-ups with parallelism?
- mrb 12y agoYes, because asymmetric problems can be parallelized.
- stromgo 12y agoIt's not so clear. Here, as long as you can afford a near-optimal SHA256 processor, more computing power doesn't help. In the "successive squaring" method (see the essay posted by gwern), as long as you can afford a near-optimal modular multiplier, more computing power doesn't help. In both approaches there is a constant cost of the near-optimal hardware, and a confidence level that the hardware is actually near-optimal. In SHA256 the cost is probably lower and the confidence level probably higher, but the difference is quantitative, and not qualitative.