[TASK] Return Cached Leaves as different format instead of Arrays

[shekohex]

Overview

Currently the relayer returns the cached leaves/encrypted outputs as a bytes array which is not optimal size-wise, for comparison:

// This just one leaf and the total size is 118 bytes
[0,96,124,186,197,202,118,215,202,188,115,135,221,48,154,82,56,200,222,123,134,81,222,24,29,150,89,62,147,193,111,174]
// the same exact leaf and the total size is 66 bytes.
"00607cbac5ca76d7cabc7387dd309a5238c8de7b8651de181d96593e93c16fae"
// Even to reduce the size further, we could reduce the size even more by using base64 (instead of hex base16)
// to just 46 bytes
"AGB8usXKdtfKvHOH3TCaUjjI3nuGUd4YHZZZPpPBb64="

• Using Arrays (Baseline) = 118 bytes.
• Using Hex strings = 66 bytes (~178% Smaller)
• Using base64 strings = 46 (~256% Smaller)

Task Checklist

• [ ] Decide which format we are going to utilize.
• [ ] Update the leaves endpoint (For EVM/Substrate)
• [ ] Update the Encrypted outputs endpoint (For EVM/Substrate)
• [ ] Update the tests
• [ ] Update the docs (README, docs site, ..etc)
• [ ] Notify the dApp team with the breaking changes in the PR.

[shekohex]

cc @AtelyPham @Nutomic and @salman01zp here to share your opinions.

[AtelyPham]

cc @AtelyPham @Nutomic and @salman01zp here to share your opinions.

+1 vote for base64 string

[salman01zp]

I will say the relayer should compute and store the Merkle root after caching leaves and just send Merkle root to Dapp. We should have separate lightweight APIs for Dapp

[shekohex]

I will say the relayer should compute and store the Merkle root after caching leaves and just send Merkle root to Dapp. We should have separate lightweight APIs for Dapp

The dApp does not just need the merkle roots, it also needs the leaves, so that they create a proving path of their mempership. If the dApp only needs the merkle roots, it is already stored in the smart contract!

[salman01zp]

will it be better as Hex String, since Dapp uses hex values to compute operations? @AtelyPham