coeniebeyers / lightning_circuit Goto Github PK

This is a SNARK implementation using libsnark for the following:

ZkPoK{ (R1, R2, R3): Hi = sha256(Ri) and R3 = R1 + R2 }

Read: given H1, H2, H3, prove you know R1, R2, R3 such that R1 is the preimage of H1, R2 is the preimage of H2, R3 is the preimage of H3, and R3 is R1 + R2.

This is an implementation and benchmark of the "Receive" zk-SNARK in the Confidential Transaction scheme from this article: https://media.consensys.net/introduction-to-zksnarks-with-examples-3283b554fc3b.

Code based on https://github.com/ebfull/lightning_circuit.

on my computer (MacBook Pro Early 2015):

• key generation time: 22.1s
• proof generation time: 5.14s
• verification time: 0.1445ss
• proof size: 2294 bits
• proving key size: 153200114 bits
• verifying key size: 4586 bits
• R1CS constraints: 83766 (mostly sha256-related)

./get-libsnark && make && ./test

• src/gadget.hpp exposes the gadget, which is an abstraction of related constraint and witness behavior in a circuit. This gadget uses other gadgets, creates its own constraints, and exposes an interface for building input maps.

• src/snark.hpp exposes a loose wrapper around the constraint system and key generation used by test.cpp to construct proofs and verify them as necessary.