prover
/ˈproʊvər/Definitions
1. noun
A person or device that proves something, especially a theorem or a mathematical statement.
“The computer program served as a prover for complex mathematical equations.”
2. noun
A person who testifies in a court of law as to the authenticity of a document or the identity of a person.
“The prover was called to the stand to testify about the signature on the contract.”