Confidential Transactions - Phase 2

Phase 2 — Beaconless Binding + Sharded Pool Plumbing for Cash-Like Payments on Bitcoin CashFundMe.cash / Flipstarter (Campaign 1 of 1)Target: 20 BCH • Duration: 45 days • Network: Chipnet (demo) • Repo: public (GitHub)One-paragraph summaryMost online payments broadcast who paid whom and how much. This campaign funds three concrete, BCH-native milestones:Sharded Pool Scaffold (on-chain demo) — a working chipnet prototype for evolving “confidential-shaped” transactions via per-user pool shards (CashTokens mutable NFTs + covenant state transitions).Reusable Packages (alpha) — factor the prototype into publishable, reusable libraries that the UI (and future work) can depend on cleanly.Desktop Demo UI (Electron — the JavaScript app framework, not Electron Cash) — a single-pane-of-glass app that runs the full demo end-to-end on chipnet and makes it easy to audit.Phase 2 ships a real on-chain skeleton + usable UX. Phase 3 (outside this campaign) can later plug in a ZKP verifier kernel for full confidentiality.Why this mattersPhysical cash doesn’t broadcast a social graph. Online payments usually do.Our goal: bring cash-like payment properties to Bitcoin Cash while keeping:No trust assumptions (no oracles, no custodians, no committees)On-chain enforceability (rules are validated by normal nodes)Standard-looking transactions (no obvious metadata beacons)What 20 BCH buys (Milestones)Milestone 1 — Sharded Pool Scaffold (Chipnet Demo)Goal: Deliver an end-to-end, on-chain sharded pool demo that evolves transaction state without requiring a global beacon or trusted party.NotesThis milestone is already substantially implemented in the current work; this funding request is being posted late. The campaign funds completion hardening: cleanup, tests, reproducible runs, and packaging into a tagged deliverable.DeliverablesA runnable chipnet demo that supports:Init: create N per-user shards as CashTokens mutable NFTs locked to a state-covenant.Deposit: create a “stealth-style” inbound payment (currently RPA-secp convenience layer).Import: move deposit value into one selected shard and mutate the shard commitment.Withdraw: spend a shard, mutate commitment again, and emit an outbound payment output.Clear documentation of what is real vs. placeholder:binding placeholders, authorization placeholders, conservation placeholders, nullifier placeholdersReproducible scripts + a state file format suitable for demos (idempotent steps)Acceptance criteria (“done when”)A clean, documented, repeatable end-to-end demo run on chipnet.Shard commitments mutate deterministically and are visible/auditable on-chain.A fresh user can follow the README to reproduce a successful run.Milestone 2 — Reusable Packages (Alpha)Goal: Turn the prototype into a small ecosystem of reusable, versioned packages that the UI can import cleanly — and that the broader BCH community can evaluate and build on.Scope note: The exact package list is intentionally open-ended. We will add/remove/merge packages as the ElectronJS UI reveals what should be stable APIs vs. demo glue. The deliverable is a coherent package set, not a fixed count.DeliverablesWorkspace packages (TypeScript-first) covering the core building blocks the demo needs, e.g.:chain scanning (RPA scan + windowed scanners)actor/wallet abstractionspool/shard operations (init/import/withdraw) with typed interfacestx building utilities (inputs/outputs, fee estimation helpers, CashTokens helpers)electrum client wrappers (typed, testable)demo state persistence interfaces (so the UI can store and replay)Packaging & publishing hygiene:correct package.json + exports maps for ESM buildsbuild outputs in dist/ with sourcemapsminimal docs per package (README + example snippet)unit tests for high-risk logic (hashing, encodings, script building, parsing)ZKP-ready “plumbing” as packages/utilities where it belongs:beaconless output binding utilities (canonical output fingerprinting)canonical hashing/transcript conventions (domain separation tags, stable parsing)budgeting hooks/guards (so later proof integration is bounded and testable)Acceptance criteria (“done when”)The demo can be run by importing only from workspace packages (no long relative imports from src/).Packages build cleanly under the pinned toolchain (Yarn 4 + TypeScript) and can be consumed as ESM.At least one end-to-end flow is covered by tests and/or deterministic test vectors (JSON fixtures).Milestone 3 — Desktop Demo UI (ElectronJS)Goal: Replace the CLI-first workflow with a packaged desktop app so non-developers can run and audit the demo end-to-end on chipnet.DeliverablesElectronJS desktop app wrapping the demo runner with UI controls for:init shardsdepositimportwithdrawUI screens replacing CLI prompts:funding screen (show address + “I funded it” → re-check UTXOs → continue)progress timeline (init → deposit → import → withdraw)live log pane (streamed events, copyable)txids + explorer links (audit-friendly)Safe, deterministic local storage for demo state and wallets in the app-data directory (not cwd).Acceptance criteria (“done when”)A new user can run the demo end-to-end on chipnet without touching the CLI.UI exposes txids, addresses, and a clear step log so observers can verify each stage in an explorer.Packaged builds run locally (at least one OS target; ideally macOS + Windows + Linux).What backers will be able to verifyBackers can independently verify progress by running the app and checking on-chain transactions:The Electron demo produces copyable txids and explorer links for every step.The sharded pool scaffold demonstrates real on-chain state evolution using CashTokens NFT commitments.Beaconless binding work (as introduced in Phase 2) avoids OP_RETURN-style beacons for binding private context to outputs.Privacy non-negotiablesWe will not ship an “efficient leak.”Only accept proofs that are truly zero-knowledge (masking/blinding isn’t optional).Never recurse/batch non-ZK proofs.Never promote witness-bearing openings into public inputs.Domain-separated randomness + no reuse across proofs/layers/batches.When funded, final Work will be delivered as public github repository under MIT license with link posted to this campaign and in Telegram channel.