Private Bridge glossary

Terp — Cosmos-SDK chain that hosts private notes and related research contracts for this product.

Private Bridge — Research product that seals a Bitcoin deposit intent, observes the deposit, and mints a Terp private note through a light-client hinge.

Deposit intent — Fixed packet locking Zcash destination, minimum out, slippage policy, expiry, bridge route ids, and intent domain bind before funding.

Deposit wallet — Fresh browser HD wallet and P2WPKH address used only for the QR fund, separate from everyday Cash App identity.

P2WPKH — Standard Bitcoin SegWit pay-to-witness-public-key-hash address type used for the one-time deposit QR.

Owner binding — Opaque destination handle derived from the Zcash address (or demo dest). Mint, swap, and open must match it.

Observation — Coordination signal that a deposit appeared on Bitcoin. Not mint authority by itself.

Re-verify — Client check of the deposit against a Bitcoin index before production-shaped mint continues.

Light-client hinge — Tip plus membership rules that admit foreign finality into the mint gate.

Burn membership — Proof that a bridge burn sits under the attested burn root at the accepted tip. Required for mint; ordinary spent-set membership is not enough.

CosmWasm — WebAssembly smart-contract runtime used on Cosmos chains, including Terp.

Headstash — CosmWasm surface that mints and burns private notes for airdrop-style claims and bridge ingress.

Claim — Separate private-note mint path (often airdrop-style) that shares the same note shape as bridge mint.

Bridge mint — Authenticated mint into a Terp private note (BridgeMintNote on headstash).

SeamNoteOut — Shared intermediate note schema (SeamNoteOutV0) for asset id, value, owner binding, commitment, nullifier lineage, and provenance pin.

Private note — Shielded note commitment on Terp; shared shape with claims and private DEX (SeamNoteOut).

Nullifier — One-shot spent or burn marker that blocks replay.

Oracle mid — Public price hint used only as a swap bound. Never mints.

Private swap — Optional spend of a private note against public virtual reserves; see Private DEX.

Zcash egress — Terp note burn followed by Zcash-side pay or mint to the sealed destination only.

Halo2 — Zero-knowledge proving system referenced for browser mint proofs when mock verify is off.

Fail closed — On re-verify or policy failure, stop as failure rather than continue as success.

Lab simulated — Explicit lab profile where synthetic observe and mock verify are allowed and labeled.

Intent domain — Versioned label on the sealed intent (for example the Bitcoin-QR funding family). Distinguishes funding policy from asset-map digests; not a user-facing brand.

SSE — Server-Sent Events; one way the UI watches deposit status without polling only.

Esplora / Electrum / Fulcrum — Bitcoin index APIs or servers the app can query to re-check a deposit. They are indexes, not mint authorities. Fulcrum is an Electrum-compatible server. A full local bitcoind node is optional for some topologies, not required for labeled lab synthetic observe.

Verifying key — Public parameters a proof verifier checks against; registered under a circuit id when real proof verify is on.

IBC — Inter-Blockchain Communication; a Cosmos message path. Not used as this product’s sealed Zcash egress.