Proposal: Canton Party Namespace Registry (CPNR)

Development Fund Proposal Submission

Proposal file: proposals/canton-party-namespace-registry.md

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Summary

This PR adds the Canton Party Namespace Registry (CPNR) proposal — a privacy-aware, decentralized registry specification and reference implementation for Canton party identifier discovery across synchronizers, eliminating the need for off-ledger party identifier exchange in multi-party workflow initiation.

Checklist

• [x] I have read the contribution guidelines
• [x] The proposal follows the template structure in proposals/_template.md
• [x] I have included a clear abstract, specification, milestones, and funding breakdown
• [x] The proposal includes adoption-based milestones with verifiable acceptance criteria

Notes for Reviewers

• Suggested label: party-portability-data-resilience
• Total funding request: 1,400,000 CC across 4 milestones
• Branch: cpnr-proposal-v2 (clean branch off canton-foundation:main — 1 commit, 1 file)