(for feedback) XXB-2026-XXX: Haven Contacts & Identity Backup Bridge via Ledger Hardware Wallet

Problem Statement
Haven users store their contacts (codenames + associated pubkeys) and identities (encrypted JSON) locally via the secure KV extension or localStorage (fallback). In case of loss, breakage, theft, or device change (smartphone, computer), recovery requires a prior manual backup (JSON export/QR code).
Without an accessible and secure backup, users lose their identity and contact networks (groups, DMs), which hinders adoption for sensitive use cases (communities, whistleblowing, high-security scenarios).
Ledger provides isolated storage already supported for xx network tokens via the “xx network” app. Reusing this for Haven contacts backup/recovery would dramatically improve resilience without compromising privacy.

Proposed Solution
Develop a third-party browser extension (Chrome + Firefox) that:

Reuses the official KV extension (XXB-2024-003) for primary storage of Haven contacts/identity.

Adds a Ledger bridge (via WebUSB/WebBluetooth) to:

Sign/derive the WOTS+ portion of contacts (via single-seed Sleeve)

Encrypt/backup a minimal contacts list (pubkeys + hashes) or derive an encryption key for the full list, with anti-duplication mechanism + contact list updates from Haven with hardware confirmations

Enable recovery: connect Ledger → unlock → import contacts/identity to a new device.

Simple UX: buttons “Backup ID/Backup Contacts to Ledger” / “Restore from Ledger” with hardware confirmations.

Optional: contact list visualization and deletion in xx.wallet with hardware confirmation.

Local passphrase fallback if no Ledger.

Open source, auditable, limited to “sign only” operations to minimize risks.

Milestones Milestone 1: Design & Proof-of-Concept

Analysis of official KV API + existing Ledger xx app.

Architecture design (WebUSB bridge, WOTS+ derivation via single seed, minimal backup format).

Minimal PoC: extension that lists contacts from KV and signs a hash via Ledger.
Deliverables: Design doc (Figma/Markdown), initial GitHub repo, PoC demo video.
Estimated cost: ??

Milestone 2: Core Implementation + Ledger Bridge

Development of third-party extension (React + JS for UI, Ledger SDK bridge).

Integration: load contacts from KV, encryption/derivation via Ledger, backup/restore flows.

Unit tests + cross-browser (Chrome/Firefox).
Deliverables: Full code, detailed README, automated tests.
Estimated cost: ??

Milestone 3: Security, Testing & Polish

Community (or external) code audit.

Beta testing with users (contact migration, device-loss scenarios).

UI polish, error handling, user documentation.
Deliverables: Audit report, beta version, tutorial.
Estimated cost: ??

Milestone 4: Publication & Final Documentation

Submission to Chrome Web Store + Firefox Add-ons.

Complete docs (how-to backup/restore, compatibility).

Forum announcement + xxDK integration examples.
Deliverables: Store links, forum update post.
Estimated cost: ??

Total Budget
50,000 USD ??

Note:
It would probably be necessary to add a “contact/group to archive” button in Haven.
Could xx.wallet allow a list view of contacts (in a dedicated section to avoid any confusion with the wallet)?

I reasonably believe the foundation could propose co-financing of 50/50 or even 70/30 to Ledger if they wish = new use case for Ledger + xx market cap is still very low.

Motorola is going to create smartphones with GrapheneOS pre-installed. That’s huge news!
Xx is an exceptional project!
I have no doubt about the project’s success.
xx + Haven + Ledger + GrapheneOS = unbeatable combo.

Thanks to the team and validators, you’re fu.king bosses!