digital signature

In computing, method of using encryption to certify the source and integrity of a particular electronic document. Because all ASCII characters look the same no matter who types them, methods have to be found to certify the origins of particular messages if they are to be legally binding for electronic commerce or other transactions. One type of digital signature commonly seen on the Net is generated by the program Pretty Good Privacy (PGP), which adds a digest of the message to the signature. Digital signatures play an essential part in authenticating electronic commerce transactions.