Code verification system

Provided is a code verification system which allows verification of a unique code in a both quick and reliable manner by using simple structure. An anti-theft ignition key device (7,8) using such a code verification system can improve the level of security and startability of an engine. By receiving a signal from a transmitter (7) for a time duration corresponding to the time duration of a unique code with a receiver, detecting a start point of a code contained in the signal, and moving a section of the signal preceding the start point to the end of the data for determining the authenticity of the thus reconstructed code as the unique code, the unique code can be verified in a both quick and reliable manner without complicating the structure.