Proposal: Canton Party Namespace Registry (CPNR)

[blackthornlover]

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

• I have read the contribution guidelines
• The proposal follows the template structure in proposals/_template.md
• I have included a clear abstract, specification, milestones, and funding breakdown
• 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)

[blackthornlover]

Hey @hythloda

Could you please apply the party-portability-data-resilience label to this PR? The CPNR proposal defines a privacy-aware, decentralized registry for Canton party identifiers, enabling cross-synchronizer party discovery without off-ledger coordination, which aligns directly with party portability and data resilience concerns.

Thank you!

[blackthornlover]

This proposal falls under the Party Portability & Data Permanence/Resilience SIG (party-portability-data-resilience). The SIG currently has no members signed up yet — if anyone from the community with relevant expertise in Canton party identity and cross-synchronizer data resilience would be interested in championing this proposal, please comment here!

As champion, you'd help advise on the proposal and support it through the Dev Fund evaluation process.

[waynecollier-da]

This proposal falls under the Party Portability & Data Permanence/Resilience SIG (party-portability-data-resilience). The SIG currently has no members signed up yet — if anyone from the community with relevant expertise in Canton party identity and cross-synchronizer data resilience would be interested in championing this proposal, please comment here!

As champion, you'd help advise on the proposal and support it through the Dev Fund evaluation process.

Sorry for the delay in responding. Can you email (wayne.collier@digitalasset.com) your contact information my way so I can add you to the SIG Slack channel for party identity and metadata?

Here's the status of the current proposals in that working group / SIG:

Data structure and overall architectural approach: canton-foundation/cips#204
Party profiles:canton-foundation/cips#169
Address resolvers: canton-foundation/cips#171
Unique issuance and name resolution: WIP; should be available soon from Axymos