ZK/SEC Research notes from zkSecurity
All posts
announcement · zk

zkBitcoin: Use Zero-Knowledge Applications (zkapps) on Bitcoin

zkbitcoin

In collaboration with Σ0, we released a new primitive called zkBitcoin, which allows for the creation of zero-knowledge applications (zkapps) on Bitcoin via a minimal layer 2 protocol that uses Bitcoin as data availability layer and a committee of participants to perform threshold signatures.

This is a significant milestone for the Bitcoin ecosystem as it augments the capability of the Bitcoin scripting language allowing for larger and more complex application. In addition, it unlocks privacy-preserving applications for Bitcoin.

We're currently running on testnet, and you can try it out by downloading the zkBitcoin CLI.

You can read the whitepaper here, which describes the two types of zkapps that can be created, stateless and stateful, while providing more details about the protocol overall:

zkbitcoin

If you like videos, you can watch:

We're excited to see what people will build on top of zkBitcoin. If you're interested in running a node for the network, or interested in using the protocol for your own application or L2, shoot us a message!

Keep reading
Recommended

Archetype x zkSecurity - Proof is in the Pudding: ZK on Bitcoin

In Session 09 of "Proof is in the Pudding," we explore the intersection of zero-knowledge proofs and Bitcoin. We break down Bitcoin's UTXO model and Script limitations, then dive deep into approaches for verifying ZK proofs on Bitcoin, from MPC-based techniques to BitVM's optimistic verification with fraud proofs. We cover timelocks, the statelessness problem and Lamport signatures for state, Taproot, simulated covenants, BitVM 3 with hashlocks and garbled circuits, cut-and-choose security, and witness encryption (BABE).

ZK/SEC · April 02, 2026

Reproducing and Exploiting ZK Circuit Vulnerabilities

Check out our latest blog post where we dive into the world of Zero-Knowledge Proof (ZKP) vulnerabilities, sharing our insights from replicating known ZK circuit weaknesses. We’ve launched a GitHub repo with detailed scripts to help you understand, reproduce, and learn from these vulnerabilities. Discover how this hands-on approach aids in grasping attack vectors, testing fixes, and enriching educational resources. Whether you're a researcher or a developer, this post is packed with info to enhance your knowledge and skills in ZKP security. Plus, find out how you can contribute to expanding this invaluable resource!

Stefanos Chaliasos, Chenyang Yu · August 09, 2024

zkSecurity took part in judging the latest zkHack Montreal

We recently had the thrill of judging the latest zkHack competition in Montreal, where developers, researchers, and enthusiasts dove into the world of zero-knowledge proofs and privacy tech. The projects were incredibly innovative, featuring creative applications like ZK breathalyzers and ZK & GPS solutions. Check out the exciting results and insights from this year's event. You won't want to miss what these brilliant minds are bringing to the table!

ZK/SEC · September 02, 2024
More to explore

WE-KZG: Encrypt to KZG.

Ever wondered if you could create a ciphertext that's only decrypted when a polynomial inside a commitment has a particular value? We’ve explored this notion using KZG commitments in our latest Asiacrypt 2024 paper. Dive into the elegant world of Witness Encryption and see how it can be applied in cool ways like Laconic Oblivious Transfer. This approach keeps things as efficient as regular KZG operations and might just spark some creative applications of your own! Curious to learn more? Let’s explore together!

Mathias Hall-Andersen · October 08, 2024

Public report of Aleo's consensus (Bullshark)

We recently audited Aleo's blockchain consensus and found it to be impressively well-documented and high-quality. Our collaboration with Aleo's cooperative team helped us uncover several key issues, and the insights from this audit were well-received. In the blog, we dive into Aleo's Bullshark consensus protocol, explaining its step-by-step process and unique pipelining techniques. We also explore how leaders ensure commitments in even rounds and discuss essential aspects like quorum intersection and garbage collection. Whether you're a blockchain enthusiast or just curious about cutting-edge consensus protocols, this post has got some fascinating details to offer!

ZK/SEC · January 02, 2024

The State of Security Tools for ZKPs

Zero-knowledge proofs (ZKPs) have come a long way from theory to real-world applications like blockchains and private transactions. We’ve been busy auditing various ZKP implementations and developing tools to improve circuit safety and security. In this blog post, we’ll explore how vulnerabilities can crop up in SNARK systems and the current state of tools designed to spot these issues. From circuit bugs to the often-overlooked frontend and backend layers, we cover how various analysis techniques and formal verification approaches are evolving to ensure robust ZKP systems. Dive in to discover the potential and current challenges in ZKP security!

ZK/SEC · June 02, 2024