Justin 4a5ef98813
Move to SHA256
SHA256 is de facto blockchain standard. Standardisation of the hash function is a prerequisite for [full standardisation of BLS12-381 signatures](https://github.com/ethereum/eth2.0-specs/issues/605). Blockchain projects are likely to provide a cheap SHA256 opcods/precompile, and unlikely to provide a Keccak256 equivelent. (Even WASM-enabled blockchains are likely to provide a SHA256 opcode/precompile since WASM does *not* natively support optimised SHA256 CPU instructions.) With Ethereum 2.0 embracing SHA256 the wider industry is more likely to converge towards a unified cross-blockchain communication scheme via Merkle receipts.

There are no security blockers with SHA256 (see comments by Dan Boneh [here](https://github.com/ethereum/eth2.0-specs/issues/612#issuecomment-470452562)).
2019-03-15 10:51:08 +00:00
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2019-03-15 10:51:08 +00:00