SHA256d Hash Rate Enhancement by L3 Cache

SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA). It has a one way compression function using the Davies-Meyer structure from a (classified) specialized block cipher. SHA-2 is utilized in secured network communications, blockchain applications etc. The mining ware of crypto currency also applies SHA-2 today. To enhance the hash rate computation power, the type of processor is changed from CPU to GPU and ASIC for different currencies. But, the issues are too much energy consumption and heavy heat from processing units. This paper's approach to enhance the hash rate computation is with higher efficiency computer resource management by L3 cache. SHA 2 application generates hash block continuously and store the block in to nearest register or cache memory. But multiple thread process configuration might create instruction stall by cache miss. We implemented L3 cache layer in the code of SHA 2 mining ware and designed higher Thread level Parallelism (TLP) inside. The result shows 531.54% higher than original mining ware program.