digital signature Forgery is a growing concern among Netizens. After all, who's to say that a message with your name on it is really from you and not somebody pretending to be you? Digital signatures are a means of proving that a file or email message belongs to a specific person, much as a driver's license proves identity in real life. Digital signatures have the added benefit of verifying that your message has not been tampered with. When you sign a message, a hash function--a computation that leaves a specific code, or "digital fingerprint"--is applied to it. If the fingerprint on the recipient's message doesn't match the original fingerprint, the message has been altered. Digital signatures are often used in combination with strong-encryption software to create a secure channel of communication, in which both privacy and identity are protected. See also: digital certificate, encryption