Theoretical minimum # of logic operations to perform double iterated SHA256? What is the theoretical minimum number of logical operations an ASIC needs to perform to compute double iterated SHA256, i.e., sha(sha(•))?
SHA256D, which is what Bitcoin uses, is 128 rounds, comprising
768 additions,
640 ORs
896 XORs
And a bunch of bit shifts but bit shifts are free on an ASIC.

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