Trapdoor Commitment

Definition ∞ A trapdoor commitment is a cryptographic scheme where a party commits to a message in a way that is binding and hiding, similar to a standard commitment scheme. However, the unique property of a trapdoor commitment is that the committer, by possessing a secret trapdoor, can later open the commitment to any message of their choosing. Without the trapdoor, the commitment remains unconditionally hiding. This specific property enables advanced cryptographic protocols. It allows for controlled malleability after commitment.
Context ∞ The concept of trapdoor commitment appears in news concerning advanced cryptographic applications, particularly in privacy-preserving technologies and zero-knowledge proofs. Discussions often center on the security assumptions and the controlled release of information enabled by the trapdoor. This primitive is a building block for more complex protocols requiring selective disclosure or conditional privacy.