Skip to main content
Opaque Protocol is documented in the opaquecash/spec repository. The SDK implements these three layers:

​
CSAP: Confidential Stealth Address Protocol

EIP-5564 stealth addresses with Opaque’s DKSAP key derivation (opaque-cash-v1 HKDF).
  • Meta-address registry
  • Stealth address announcer
  • View-tag prefilter + WASM ownership scan
Spec: CSAP.md SDK surface: Stealth API, Stealth payments concept

​
PSR: Provable Stealth Reputation

Schema registry, attestation engine, and Groth16 reputation verifier. Attestations bind to stealth_address_hash, not a public EOA.
  • V2 schemas with ABI-style field definitions
  • Delegated issuance (up to 10 delegates)
  • Discovery announcements with attestation metadata
  • ZK proofs scoped by externalNullifier
Spec: PSR.md SDK surface: PSR API, PSR concept

​
UAB: Universal Announcement Bus

Cross-chain relay of 96-byte stealth announcement payloads over Wormhole.
  • UABSender.announceWithRelay on source chain
  • UABReceiver re-emits on destination chain
  • Off-chain relayer delivers VAAs
Spec: UAB.md SDK surface: Cross-chain API, Cross-chain concept

​
Repositories