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digital signature

Broader Term: 

n. ~ A code, generally created using a public key infrastructure (PKI) associated with a digital object that can verify the object has not been altered and, in some contexts, may be used to authenticate the identity of the sender.


A digital signature is typically a message digest that is derived from the digital object being signed and encoded with a public key. The recipient can use the message digest to ensure that the object has not been altered and can use the matching private key to ensure the identity of the sender.

See American Bar Association, Information Security Committee, Digital Signature Guidelines at

(ABA, p. 3) From the information security point of view, 'Digital signature' means the result of applying to specific information certain specific technical processes described below. The historical legal concept of 'signature' is broader. It recognizes any mark made with the intention of authenticating the marked document. [Note: See, e.g., U.C.C. §1-201(39) (1992).] In a digital setting, today's broad legal concept of 'signature' may well include markings as diverse as digitized images of paper signatures, typed notations such as '/s/ John Smith,' or even addressing notations, such as electronic mail origination headers.
(Webopedia website) A digital code that can be attached to an electronically transmitted message that uniquely identifies the sender. Like a written signature, the purpose of a digital signature is to guarantee that the individual sending the message really is who he or she claims to be. Digital signatures are especially important for electronic commerce and are a key component of most authentication schemes. To be effective, digital signatures must be unforgeable. There are a number of different encryption techniques to guarantee this level of security.