gr3yc4t / secure-computation-project

Implementation of a smart contract responsible for keeping track of redactable blockchain modification

Secure Computation Project

Implementation of a smart contract responsible for keeping track of redactable blockchain modification

Requirements

• Solidity Compiler
• Zokrates

Alternatively you could use the Remix IDE with the Zokreates plugin.

Building

• Compile locally_redactable_nizk.zok with Zokrates and generate verifier.sol
• Compile KeyManagementOracle.sol with a Solidity compiler (e.g. solc)

Usage

The contract must be initialized with the scheme parameter k and a commitment to the trapdoor key. The Pedersen commitment requires two point G, H that can be generated using the script inside commitment_generation.

When the method FinalizeCollision is called, the parameters a, b and c represent the zk-SNARKs proof generated by Zokrates. Instead, c0 and c1 represent the i-th collision key of the scheme divided in two field element. See how sha256packed works in Zokrates for better understanding.

secure-computation-project's Issues

Pedersen Commitment Insecure

The implementation of the Pedersen Commitments you have is insecure. G and H need to be group elements, not field elements. It is easy to equivocate commitments here.