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# System prepended metadata

title: Ethereum cohort week 14

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# Ethereum cohort week 14


This week I finally finished pedersen hash and commitment specified here: https://hackmd.io/kr5Gka1-S82evw4ex9_OBA

And tested against go-verkle:


> -- Pedersen hashing: https://pastebin.com/0RrL3Ryc
> The format is:
> addr: bytes in hex
> treeIndex: The big int number in decimal notation (base 10). It's a "string" because I can put such a big integer in a JSON.
> treeKey: the result of the perdersen hash bytes
> 
> -- Vec comm: https://pastebin.com/dJyzwXnB
> The format is:
> frs: a slice of 256  integers (the Frs)
> commitment: The resulting big int. [Remember that Pedersen Commitment gives you a point, then you have to do MapToScalar which gives you a Fr. This Fr is here as a big integer]


Here's the PR:
https://github.com/Quadratic-Labs/VerkleTries_Besu/pull/43


Also spend some time reading MPT circuit:
https://trapdoortech.medium.com/zero-knowledge-proof-deep-into-zkevm-source-code-mpt-circuit-fb2dba6e8ba3


And I have finally understood that following the root of the trie is separate thing from producing the proof for the values in the trie.

This is very important for the context of the architecture of ethereum L1 full node, stateless clients, and zkEVMs.