Creator

Nicola

Created

Feb 9, 2022 12:34 PM

Stage

Still Valid

If we have a way to prove that two merkle trees are different then we can solve the following problems.

If we solve problem 1, we don't have to solve problem 2.

Storage IPFS hashes

Goal:

Store data via IPFS hash

Setting:

• Client gives IPFS hash to miner
• Miner turns it into a PieceCID
• Miner makes the deal with IPFS CID field and PieceCID field
• When a user gets the file back from the miner, they can check if the file matches the IPFS CID
• If the IPFS CID is not matched, then they can post a proof that this mapping was incorrect

Actual proof:

• Find the branch of the IPFS DAG and the branch of the PieceCID where the data differ
• Generate a merkle proof for each
• (Option: if the proof is too big: SNARK those proofs)
• Send proof on-chain

Next steps:

SNARK Friendly Data Structures: Simpler IPLD for SNARK friendly circuits

Poseidon CommD on-chain for faster SnapDeals

See SnapDeals with Reduced Overhead - Adopting alternative Data Commitment

Goal:

Make the proofs for SnapDeals to be super cheap by having CommD generated with Poseidon without the client running Poseidon.

Setting:

• Client gives ShaCommD to miner
• Miner turns it into PoseidonCommD
• Miner makes the deal with PoseidonCommD and ShaCommD
• When user gets the file back, they can check if their file matches ShaCommD
• If the file does not match ShaCommD, they can post a proof

Actual proof:

• Find the branch of PoseidonCommD and the branch of ShaCommD where the branch disagree
• Generate merkle tree proof for each
• (Option: if the proof is too big: SNARK those proof)
• Send proof on chain

Cons:

• Who puts the collateral to be slashed? can we reuse the deal collateral?