Skillful and determined hacker will compromise even computers of the Department of Defense. Security, that no hacker can bypass does not exist.

An ethical hacker is someone who attacks the security systems of a computer and network with the consent of its owners. Ethical hackers are used to test the security of a system and seek ways to improve it.

The term hacker has a double meaning within the field of computing. A hacker can be a genuine expert of computer software and hardware. The other known meaning of hacker is someone who breaks into computer security networks for a reason of their own, basically they break the law in doing so.

Exstensive knowledge of computer and software security, lots of programming skills, and ingenuity.

Hacker, security cracker, or penetration tester (for legitimate purposes only)