Page 442 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

valid)

Subject’s name (contains the distinguished name, or DN, of the
entity that owns the public key contained in the certificate)

Subject’s public key (the meat of the certificate—the actual public
key the certificate owner used to set up secure communications)

The current version of X.509 (version 3) supports certificate
extensions—customized variables containing data inserted into the
certificate by the certificate authority to support tracking of certificates
or various applications.

If you’re interested in building your own X.509 certificates

or just want to explore the inner workings of the public key
infrastructure, you can purchase the complete official X.509

standard from the International Telecommunications Union (ITU).
It’s part of the Open Systems Interconnection (OSI) series of
communication standards and can be purchased electronically on
the ITU website at www.itu.int.

Certificate Authorities

Certificate authorities (CAs) are the glue that binds the public key
infrastructure together. These neutral organizations offer notarization

services for digital certificates. To obtain a digital certificate from a
reputable CA, you must prove your identity to the satisfaction of the
CA. The following list includes some of the major CAs that provide
widely accepted digital certificates:

Symantec

IdenTrust

Amazon Web Services

GlobalSign

Comodo

Certum