Pro PHP Security: From Application Security Principles to the Implementation of XSS Defenses, Second Edition

What Is Computer Security?

Computer security is often thought of as a simple matter of keeping private data private. That is part of the concept, perhaps even the most important part; but there are other parts also. We see three issues at the heart of computer security:

• Secrets: Computers are information systems, and some information is necessarily proprietary. This information might include the passwords and keys that protect access to the system's scarce resources, the data that allows access to users' identities, and even actual real-life secrets that could affect physical safety. Security in this respect is about making sure that such secrets do not fall into the wrong hands, so that spammers can't use a server to relay spam email, crooks ...