Trustless, atomic, private OTC settlement for large block trades

What this enables

• →Trustless large block trading. FTX and Genesis were both OTC desks that went bankrupt with client funds. This removes the intermediary entirely - atomic settlement via a verifiable Cairo contract, no admin keys.
• →Privacy that institutions can actually use. Both parties generate viewing-key trade confirmations for their compliance teams. The auditing entity can trace specific trades under legal process. Privacy through cryptography, not through opacity.
• →Fee compression for the OTC market. Traditional desks charge 10–50bps for matching, custody, and settlement. STRK20 OTC automates the last two. Fees collapse to 5–15bps - the cost of matching alone.
• →Channel-based counterparty relationships. A market maker with 50 regular counterparties has 50 encrypted, persistent channels. Subsequent trades are frictionless: no new on-chain setup, no re-KYC, no address leakage.

What you build

An OTCSettlement helper contract with a two-leg fill pattern: seller fills leg A, buyer fills leg B in the matching transaction, settlement is atomic on leg B (verify, fee, distribute via open_note_deposit, mark settled). Timeout-and-reclaim for the cancel path. Counterparty discovery is a separate layer - start with off-chain matching (Telegram/Discord OTC groups), extend to on-chain encrypted intent boards or automated RFQ later.

Hidden vs visible

| Element | Hidden | Visible | | --- | --- | --- | | Both parties' identities | Yes - paymaster submits, no address link | | | The relationship between them | Yes - channels are encrypted | | | Trade amounts, token pair | | Both parties already know - open notes are plaintext | | That an OTC trade occurred | | Yes - deposits to and distributions from the helper | | Compliance history | Selectively - via each party's own viewing key | Not public |

Why it ships

The privacy pool already provides the three things traditional OTC desks charge for: privacy (cryptographic, not opacity-based), settlement (atomic, no human in the loop), and compliance (selective disclosure via viewing keys). The desk's value collapses to matching - everything else is better done by the protocol.