Adaptor Signature

Overview

An adaptor signature is a pre-signature that cannot yet authorize the final transaction but can be completed by someone who knows a specific secret. Comparing the completed signature with the adaptor form can reveal that secret to the intended counterparty.

This property enables scriptless conditional payments, atomic swaps, and payment-channel protocols without placing the full condition directly in an on-chain script. Security depends on the underlying signature scheme, correct proof construction, nonce handling, and careful binding to the intended message.

Implementation errors can leak keys, permit replay, break atomicity, or expose transaction relationships. Developers should use reviewed protocols and libraries, separate keys and nonces correctly, validate proofs, and test abort, timeout, and malformed-message scenarios.

For Adaptor Signature, an indicator supplies evidence, a control changes exposure, a policy states expectations, and an incident records an event; using those labels interchangeably obscures decisions.

For Adaptor Signature, teams should measure unnecessary friction, exclusion, delay, privacy intrusion, failed recovery, and inconsistent treatment while preserving the safeguards needed for material wallet and custody exposure.

An adaptor signature is a cryptographic construction that hides a secret inside an incomplete signature and reveals it when completed. Adaptor signatures enable private conditional transactions, but subtle protocol or nonce errors can defeat atomicity and compromise signing keys.

A production treatment of Adaptor Signature should test a cryptographic construction that hides a secret inside an incomplete signature and reveals it when completed within the relevant asset, decision, or service state. The Adaptor Signature context record for a cryptographic construction that hides a should preserve source data, configuration or policy version, responsible actor, exception, and outcome. Review of Adaptor Signature should determine whether safeguards addressing a cryptographic construction that hides a changed exposure in practice, not merely whether a document or setting existed.