contract-lock

Contract lock is a platform, where the any 2 parties can share agreements and verify if the intended party is the one who agreed to the document.

What would happen when someone joins a company ? Apart from him or she trying to fit into the new environment and skill set, they would need to sign forms and agree to some of the rules and conditions or maybe sign an NDA. Right now most of the companies use something called contract book. It's a centralised party which arranges signing between two parties. And sometimes the companies can change the contents of the form without informing the employee. And maybe the user wants to check a particular point in the form they signed but he can't find it anymore. Centralisation at peaks. Let's put a stop to it with Contract Lock!

The flow starts with user registration through the Self app, where users sign up using a valid identity document. Each user is assigned a unique identifier called a nullifier.

Once registered, a user (Party A) can create an agreement for another user (Party B). The agreement is generated as a PDF, encrypted using the Lit protocol, and stored securely.

Access to the document is strictly controlled. Only the two parties involved (A and B) can decrypt and view the file. This is made possible through a key management system that uses threshold cryptography and multi-party computation (MPC), ensuring that no single network node can decrypt the document on its own.

When Party B, the intended signer, receives the contract, they can decrypt and review the content. If the contract is correct, they sign it. Upon signing, an NFT is minted to represent the signature. This NFT serves as an on-chain proof and contains the encrypted content hash (stored on IPFS) along with the user’s nullifier from the Self protocol in its metadata.

This design guarantees that once an agreement is signed, it cannot be altered.

The system is built as a decentralized alternative to Contractbook (https://contractbook.com/ ), a web2 product that openly positions itself as a centralized entity. The key advantage of our approach is that, while running fully on decentralized infrastructure, the user experience is as smooth and convenient as any web2 product. Users don’t even realize they are interacting with a web3 system.