Abstract: A "state of the art" Computer Security Processor (CSP) is disclosed to stop the "hacker" (a person who enjoys computers as a hobby) by making it virtually impossible to "break into" (a term meaning to falsely gain access to) a computer. A processor is disclosed comprising two units, a transmitter and a receiver. The transmitter sends a special code over the telephone line to the receiver which recognizes a correct or a fraudulent code and then allows access to the host computer provided the code is correct. The unit uses special frequencies other than Touch Tone.RTM., and additionally boasts a wide variety of security codes numbering 8.sup.10 power. These codes can be changed as often as desired. The unit is lightweight, small, and has a low power drain, yet is extremely effective. The transmitter is self-contained and fully portable. The receiver uses normal 120 VAC current and is also portable. Both these units can be built in small housings.