Digital Certificates

Digital Certificates

As you learned in Chapters 9 and 11, a digital certificate is a form of credential, much like a driver’s license or a passport in the paper-based world. Like its paper counterparts, the digital certificate has information on it that identifies the holder, plus the certificate authorities (CA), a trusted third-party that “signs” the certificates to confirm the holder’s identity.

A digital certificate has additional information included with the holder’s public key, which helps others to verify the key is genuine. This additional information, like a person’s picture on a driver’s license or a passport, can thwart attempts to substitute an unauthorized public key.

A digital certificate contains the following three items:

• Public key

• Certificate information�"Identifying information about the holder, such as IP address, name, serial number, company, department, and so forth

• One or more digital signatures�"Supplied by a CA