circ/doc/zkp.md

Quickstart for ZKPs using the Z# front-end

1. Configure CirC's example compiler: ./driver.py --features bellman r1cs poly zok

• turns on the bellman ZKP backend, the R1CS compiler extension needed to target it, support for finite field polynomials, and the Z# (an extended ZoKrates) frontend

2. Build the CirC library and example compiler ./driver.py -b
3. Compile an example program to ZKPs and sample ZKP paramaters: ./target/release/examples/circ examples/ZoKrates/pf/maj.zok r1cs --action setup

• creates a proving key in file ./P
• creates a verifying key in file ./V
• The program does a bitwise majority of three 8-bit arguments; the inputs are secret, the output is public.

4. Create a proof: ./target/release/examples/zk --inputs examples/ZoKrates/pf/maj.zok.pin --action prove

• creates a proof in file ./pi
• the (secret) program inputs are in the input file examples/ZoKrates/pf/maj.zok.pin

5. Verify the proof against a claimed program output: ./target/release/examples/zk --inputs examples/ZoKrates/pf/maj.zok.vin --action verify

• the output is return in the input file examples/ZoKrates/pf/maj.zok.vin
• if verification fails, the command will return an error