What is a digital signature?

•    A digital signature functions for electronic documents like a handwritten signature does for printed documents. The signature is an unforgivable piece of data that asserts that a named person wrote or otherwise agreed to the document to which the signature is attached.

•    A digital signature actually provides a greater degree of security than a handwritten signature. The recipient of a digitally signed message can verify both that the message originated from the person whose signature is attached and that the message has not been altered either intentionally or accidentally since it was signed. Furthermore, secure digital signatures cannot be repudiated; the signer of a document cannot later disown it by claiming the signature was forged.

•    In other words, Digital Signatures enable "authentication" of digital messages, assuring the recipient of a digital message of both the identity of the sender and the integrity of the message.