ZKP Circom (1)

本文主要是介绍ZKP Circom (1)，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

MIT IAP 2023 Modern Zero Knowledge Cryptography

Lecture 2: Circom 1 (Brain Gu)

• Review zkSNARKs
  

  • Properies
    • zk: hides inputs
    • Succinct: generates short proofs that can be verified quickly
    • Noninteractive: doesn’t require a back-and-forth
    • ARgument of Knowledge: proves you know the input

• Generate a ZKP for satisfiability of the R1CS

  • x_i + x_j = x_k
  • x_i * x_j = x_k

• zkSNARKs Example
  

• zkSNARKs prove constraints

  • Example 1
    

  • Example 2
    

- A bug in the code: x3 should be constrained to x3 != 0

• Circom Demo
  • ZKRepl: zkrepl.dev
  • Example 1

pragma circom 2.1.6;template Example() {signal input x1;signal input x2;signal input x3;signal input x4;signal input y1;signal input y2;signal input out;y1 === x1 + x2;y2 === y1 * x3;y2 === out + x4;
}component main {public [out] } = Example();/*
INPUT = {"x1" : "2","x2" : "4","x3" : "8","x4" : "5","y1" : "6","y2" : "48","out": "43"
}
*/

- Output

STDOUT: 
template instances: 1
non-linear constraints: 1
linear constraints: 0
public inputs: 1
public outputs: 0
private inputs: 6
private outputs: 0
wires: 6
labels: 8
Written successfully: ./main.r1cs
Written successfully: ./main.sym
Written successfully: ./main_js/main.wasm
Everything went okay, circom safe
Compiled in 0.32s
ARTIFACTS: 
Finished in 0.43s
main.wasm (34.45KB)
main.js (9.18KB)
main.wtns (0.27KB)
main.r1cs (0.35KB)
main.sym (0.10KB)
PLONK KEYS: 
main.plonk.zkey (13.59KB)
main.plonk.vkey.json (2.00KB)
main.plonk.sol (23.38KB)
main.plonk.html (477.04KB)

• Example 2: Num2Bits

pragma circom 2.1.6;template Bits4(){ //range checksignal input in;signal bits[4];var bitsum = 0;for (var i = 0; i < 4; i++) {bits[i] <-- (in >> i) & 1;bits[i] * (bits[i] - 1) === 0;bitsum = bitsum + 2 ** i * bits[i];}bitsum === in;
}template Num2Bits() {signal input in;signal input b0;signal input b1;signal input b2;signal input b3;component check = Bits4();check.in <== in;in === 8 * b3 + 4 * b2 + 2 * b1 + b0;b0 * (b0 - 1) === 0;b1 * (b1 - 1) === 0;b2 * (b2 - 1) === 0;b3 * (b3 - 1) === 0;}component main { public [b0, b1, b2, b3] } = Num2Bits();/*
INPUT = {"in" : "11","b0" : "1","b1" : "1","b2" : "0","b3" : "1"
}*/

• Output

STDOUT: 
template instances: 2
non-linear constraints: 8
linear constraints: 0
public inputs: 4
public outputs: 0
private inputs: 1
private outputs: 0
wires: 8
labels: 11
Written successfully: ./main.r1cs
Written successfully: ./main.sym
Written successfully: ./main_js/main.wasm
Everything went okay, circom safe
Compiled in 1.08s
ARTIFACTS: 
Finished in 1.16s
main.wasm (35.85KB)
main.js (9.18KB)
main.wtns (0.33KB)
main.r1cs (1.57KB)
main.sym (0.19KB)
PLONK KEYS: 
main.plonk.zkey (66.00KB)
main.plonk.vkey.json (2.00KB)
main.plonk.sol (28.36KB)
main.plonk.html (548.77KB)

• Some improvement

pragma circom 2.1.6;template RangeCheck(nBits){ //range checksignal input in;signal bits[nBits];var bitsum = 0;for (var i = 0; i < nBits; i++) {bits[i] <-- (in >> i) & 1;bits[i] * (bits[i] - 1) === 0;bitsum = bitsum + 2 ** i * bits[i];}bitsum === in;
}template Num2Bits(nBits) {signal input in;signal input b[nBits];component check = RangeCheck(nBits);check.in <== in;var accum = 0;for (var i = 0; i < nBits; i++){accum += (2 ** i) * b[i];}in === accum;for (var i = 0; i < nBits; i++){0 === b[i] * (b[i] - 1);}}component main { public [b] } = Num2Bits(4);/*
INPUT = {"in" : "11","b": ["1","1","0","1"]
}
*/

这篇关于ZKP Circom (1)的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---