attestation

noun attestation

• corroboration — the act of corroborating.
• testimonial — a written declaration certifying to a person's character, conduct, or qualifications, or to the value, excellence, etc., of a thing; a letter or written statement of recommendation.
• testimony — Law. the statement or declaration of a witness under oath or affirmation, usually in court.
• authentication — to establish as genuine.
• declaration — A declaration is an official announcement or statement.