Module read_proof

This module defines the read proof prover and verifier. Given a query vector q, a vector of data d, and a commitment to this data C, the prover will return an answer a and a proof that the answers correspond to the data committed in C at the specified indexes in the query.

The folding version is TBD We call data the data vector that is stored and queried We call answer the vector such that answer[i] = data[i] * query[i]

The considered protocol involves a user, the chain and the storage provider and behaves as following:

1. The user sends a request to the chain, containing a commitment to a data handled by the storage provider with a query that specifies which indexes to read.
2. The chains includes the query if it’s valid and computes the commitment to the query.
3. The state replicator fetch the request with the data & query commitments on the chain, computes the corresponding answer & proof, and sends it to the chain.
4. The chain includes the proof if it verifies, and if it’s consistent with the provided answer.

Structs

Answer

Answer to a query regarding some data

Query

Indexes of the data to be read ; this will be stored onchain Note: indexes are represented with u16, matching indexes from 0 to 2¹⁶ - 1. If the SRS is made bigger, the integer type has to handle this

ReadProof

Functions

prove

verify

verify_answer

Checks that the provided answer is consistent with the proof Here, we just recompute the commitment TODO: could we just recompute the evaluation ?