Glossary of Digital Signature Terms

Algorithm - A rule or procedure for solving a logical or mathematical problem.

Authentication - The process of identifying an individual or data. In security systems, authentication is distinct from authorization. Authentication merely confirms that the identification of the individual or data is accurate.

Certification Authority - A certification authority, or CA, is the person or company who issues digital certificates to subscribers. They act as a trusted "third party" certifying the identity of the subscriber to anyone who receives a digitally signed message.

Cryptographic Algorithm - A specialized algorithm used to encrypt or decrypt data.

Digital Signature - A process which can be used to attach to an electronic message a digital code that is unique to the "signer" of the message. A digital signature results from the use of a "Private Key" to "sign" a message. The recipient of the electronic message can use the signer's "Public Key" to verify whether or not the digital signature is valid, and whether the message has been altered since it was signed.

Electronic Commerce - Any commercial activity that takes place, at least in part, between connected computers is part of electronic commerce. It is often referred to as "eCommerce".

Encryption - The process of encoding data in a way that prevent unauthorized viewing, especially while the data is being transmitted. This process makes the data content unreadable to everyone except those who have the correct key to "decrypt" the data.

Keys - Pieces of information that are used to encrypt or decrypt a message. The key can "lock" data and make it unreadable, and a corresponding key can "unlock" that data and allow use of that data. In most digital signature programs, keys are very long prime numbers.

Operative Personnel - The are the people who perform sensitive duties for a certification authority or repository. Commonly, these are people who maintain the systems, issue certificates, or establish certification policies.

Prime Number - A number, greater than 1,  which has two divisors, 1 and itself.

Repository - A repository is a database that stores digital certificates, so that digitally signed messages can be verified for authenticity.

If there is an Electronic Authentication term used in this web site that you do not understand, please email the Electronic Authentication Program at