Attester and Testifier

Attester noun - Someone who affirms or vouches for the correctness or truth or genuineness of something.

Testifier and attester are semantically related in witness topic. In some cases you can use "Testifier" instead a noun "Attester", when it comes to topics like law.

Testifier noun - A person who testifies or gives a deposition.

Attester and testifier are semantically related in witness topic. You can use "Attester" instead a noun "Testifier", if it concerns topics such as law.