- A passphrase is a string of characters longer than the usual password (which is typically from four to 16 characters long) that is used in creating a digital signature (an encoded signature that proves to someone that it was really you who sent a message) or in an encryption or a decryption of a message. For example, Phil Zimmermann's popular encryption program, Pretty Good Privacy, requires a passphrase when you sign or decrypt a message. Passphrases are often up to 100 characters in length.
TechTarget provides enterprise IT professionals with the information they need to perform their jobs - from developing strategy, to making cost-effective IT purchase decisions and managing their organizations' IT projects - with its network of technology-specific Web sites, events and magazines.
- A passphrase is a string of 
