Solid State Key/Lock Security System

In the field of security systems, many soultions have been devised aimed at implementing a "true electronic key" but they are unsatisfactory due to the need of electrical contacts with the lock or of power supply in the remote control systems. In addition, some solutions are not 100% secure because the access code canbe easily copied or falsified; so the best solution is a system that has the following features:--No electrical contacts with the Code Receiver, thus avoiding defective operations in the presence of dirt.-An adequate amount of internal non-volatile coding storage, so as to have a large number of possible combinations.-As greater difficulty as possible in copying or falsifying the internal code.