White hat hackers, also known as ethical hackers, or white knights, are computer security experts, who specialize in penetration testing, and other testing methodologies, to ensure that a company's information systems are secure. Such people are employed by companies where these professionals are sometimes called "sneakers". Groups of these people are often called tiger teams or red teams. These security experts may utilize a variety of methods to carry out their tests, including social engineering tactics, use of hacking tools, and attempts to evade security to gain entry into secured areas.
The National Security Agency offers certifications such as the CNSS 4011. Such a certification covers orderly, ethical hacking techniques and team management. Aggressor teams are called "red" teams. Defender teams are called "blue" teams.