 function of a signature in, is attached to, or is logically associated with a record, and is used by a signatory to take responsibility for, or to give consent to, the content of the record. [Archives] 
n., A code, generally created using a public key infrastructure (PKI), that is associated with a digital object that can verify that the
object has not been altered and, in some contexts, may be used to authenticate the identity of the sender. [Computer a
nd
Information Sciences] 
n., An electronic signatur