attest

Attest is a verb meaning to bear witness to the truth of something or to certify the authenticity or accuracy of a statement, document, or claim. It can involve witnessing an event, validating information, or endorsing a document by signing or providing certification.

The word derives from Latin attestare, through Old French atester, and entered English in the late Middle Ages. In modern usage, attest conveys both personal testimony and formal authentication.

In legal contexts, an attesting witness signs to confirm the execution of a will, deed, or contract. Many jurisdictions require the attesting witness to be impartial and not a beneficiary. An attestation clause on a document records that it was properly signed, witnessed, and delivered.

Beyond law, to attest can also mean to certify the accuracy of information or the validity of a claim, or to provide a certificate attesting to a person’s identity, qualifications, or status. In everyday language, one might attest to the reliability of a source or the truth of a statement.

In information security and computing, attestation refers to a process by which a system proves its integrity to a remote party, typically through cryptographic measurements and proofs. This modern usage extends the sense of providing evidence of truth or genuineness into technical assurance.

Attest is related to the noun attestation and to verbs such as testify. While attest emphasizes certification or evidence, testify emphasizes giving formal, often oath-bound, testimony.