ClauseHash

Private, Wallet-Signed Document Attestations. Useful for attestation in legal and policy workflows.

ClauseHash

Created At

ETHGlobal Tokyo 2026

Project Description

ClauseHash is a local-first document integrity tool for legal and policy workflows. You paste sensitive text, it gets canonicalized and SHA-256 hashed entirely in the browser, then your wallet signs a readable attestation with the title, jurisdiction, fingerprint, and timestamp. The exported JSON receipt excludes the source text, and anyone can import it alongside a document to verify hash consistency locally. Vanilla JS, browser-native APIs, no backend, no contract.

How it's Made

Vanilla JS + ES modules, which keeps it nice and simple (quite rare in 2026 with all the frameworks we have). Text is canonicalized (LF, trimmed), and the SHA-256 is hashed via Web Crypto. These are all pretty standard architectural choices. Your wallet signs a readable attestation with personal_sign and exports a JSON receipt with no document text. It can verify re-hashes locally.

I did use some AI help in building this, but the idea was from myself and is relevant to my legal and technical background. Nothing in particular was hacky, this is more just a simple utility app.

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