Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
SHA256 is de facto blockchain standard. Standardisation of the hash function is a prerequisite for full standardisation of BLS12-381 signatures. Blockchain projects are likely to provide a cheap SHA256 opcode/precompile, and unlikely to provide a Keccak256 equivalent. (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).