Intel has been awarded patent #10,142,098 , which pertains to a system they’ve designed which improves the energy efficiency of Bitcoin miners. While it takes a hardware engineer to fully understand what’s going on in their patent, relevant to the discussion is the following quote: […] certain portions of the input message, state data, and input values to multi-stage SHA-256 engines 110, 112, 114 may be fixed to constant data values during SHA-256 hashes or during certain rounds of computation in the SHA-256 hash. Rather than providing these constants using registers, embodiments of the present disclosure hardwire ... (full story)