Let's Seal: The Open Standard for Free File Authentication

Let's Seal is an open-source initiative providing a free standard for cryptographic file authentication and timestamping. By anchoring proofs to Bitcoin and using public transparency logs, it allows anyone to verify that a document is unaltered and issued by a specific entity. The project offers a suite of tools, including a web app and CLI, to make secure document sealing accessible to everyone.

Key Points

• Let's Seal establishes SEAL as an open standard for proving file integrity, timing, and authorship without proprietary lock-in.
• The system utilizes Bitcoin anchoring and public transparency logs to ensure proofs are tamper-evident and verifiable forever without trusting a central authority.
• It supports a wide range of native file formats, such as PDF, XML, and C2PA-compliant media, allowing for universal verification.
• The project is entirely open-source (Apache-2.0) and offers free tools including a web app, CLI, and self-hostable signing services.
• Issuer identity is managed through domain control verification, similar to the TLS model used for securing websites.

Sentiment

Cautiously optimistic but skeptical regarding business adoption and legal validity.

In Agreement

• The current 'pay-to-play' model for document verification and Adobe's walled garden are significant problems that need an open-source solution.
• The use of familiar naming conventions and syntax from Let's Encrypt makes the tool intuitive for developers.
• The technical foundation of using PAdES, transparency logs, and Bitcoin anchoring is seen as a solid approach to decentralized proof of existence.
• The project successfully provides a way to verify documents without requiring the verifier to have a specific account or proprietary software.

Opposed

• The tool lacks critical business features such as document templates, API-driven autofill, and optional form fields (e.g., optional checkboxes).
• Legal recognition in courts is uncertain, as many jurisdictions still prioritize traditional signatures or established digital standards over new cryptographic methods.
• Establishing a 'trust anchor' is difficult for a new project; conservative organizations are unlikely to adopt a standard that lacks official RFC or ISO backing.
• The project may be contributing to standards fragmentation (referencing XKCD 927) rather than solving it.
• There are technical questions about whether it can meet higher PAdES standards (like B-T) without a QTSP timestamp.