Refers to the signature file or document signed by the signer himself without any copying or modification, that is, the original version directly signed by the signer himself. Original signature usually refers to the original electronic document in electronic signature or the original paper document with handwritten signature. The function of the original signature is to confirm the identity of the signer, the time of signing and the authenticity and integrity of the signature content, so as to facilitate the traceability and review of the signature behavior. In law, the original signature usually has evidential value and can be used as evidence to prove the authenticity and legitimacy of the signature.