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