Deposit screening
Proof of innocence works best if obviously illicit money never gets in to begin with. So Murk screens deposits at the door.
How it works
When you veil funds, your wallet builds the deposit transaction and sends it to Murk's screening service for a co-signature. That service checks the address the deposit is coming from against the sanctioned-address data published for the OFAC Specially Designated Nationals list — the maintained public feed of sanctioned digital-currency addresses, covering Solana and every other listed currency, refreshed daily.
- If the source address is not on the list, the service co-signs and your deposit proceeds normally.
- If it is, the service declines to sign, and the deposit cannot enter the pool. Your funds never leave your wallet.
The on-chain program enforces this: while a screening key is configured, a deposit without that co-signature is rejected. It also requires the deposit to be a top-level instruction, so no other program can wrap a deposit and ride a signature that was issued for something else.
The current Murk deployment has screening switched on.
What it is and isn't
- It signs, it doesn't hold. The screening service never holds a balance, never submits a transaction, and never touches the pool. It only adds a signature to a transaction you already built and signed.
- It's fail-closed. If the sanctions data has never loaded, the service refuses to sign anything rather than waving deposits through.
- It is an address check, not KYC. You are not identified, and no personal information is collected. It compares one public address against a published list.
- It's a floor, not a ceiling. Screening catches known-sanctioned sources at entry. Money that is only later found to be illicit is handled by revocation instead — the two are complementary, and neither replaces the other.
- It's replaceable. The check sits behind a single endpoint, so a commercial transaction-monitoring provider can be added or substituted without any change to the pool, the circuits or your notes.