Data security is the discipline of protecting data from unauthorized destruction, modification, or disclosure. In short, data security includes everything individuals, companies, governments, and other organisations have to do to protect their data; and this ranges from proper electronic security to having security guards patrolling the building at night.

This field is often considered to be synonymous with cryptography, but while the practical aspects of data security draw heavily on encryption and cryptographic techniques in general, it actually comprises much more than this single topic.

The elements of data security are often thought of as belonging to four broad areas:

• 1. authentication, authorization, accountability, and audit
• 2. confidentiality
• 3. availability
• 4. integrity

Every situation where data security is a consideration will mean dealing with one or more of these areas.

Authentication is the process of proving an identity, either of a person or of a machine or process. The identity...