merkle tee with sha256?!

[cryptonian-base]

I've been trying to make zkSNARK for merkle tree with sha256.

Merkle tree with mimc is given as an example in this repo but replacing mimc with sha256_full or sha256_many has been found not that easy task.

Anyone has tried the same thing? Any advice will be welcome :)

[HarryR]

For merkle-tree with SHA256, see an example at:

https://github.com/barryWhiteHat/miximus/blob/master/src/main.cpp#L84

This uses the two gadgets from libsnark:

• merkle_authentication_path_variable
• merkle_tree_check_read_gadget

These can be used in-conjunction with the SHA256 gadgets from Ethsnarks to make hashes which are compatible with Ethereum.

• https://github.com/HarryR/ethsnarks/blob/master/src/gadgets/sha256_many.cpp (takes arbitrary length input, does arbitrary padding)
• https://github.com/HarryR/ethsnarks/blob/master/src/gadgets/sha256_full.hpp (only accepts a 512bit input)

An Ethereum-compatible solidity library for doing merkle tree with SHA256 is:

• https://github.com/barryWhiteHat/miximus/blob/master/contracts/MerkelTree.sol