System and procedure for protection against the analytical espionage of secret information

Abstract

The invention presented describes a system and procedure for protecting against the espionage of secret information. A counter is allocated to each secret piece of information, in particular codes. The counter counts the number of uses of the secret information. In this, the counter is set to a starting value. Each use of the secret data element increases the counter state by a defined value. If the counter state reaches a maximum value, the use of the secret data element will be blocked. The blocking of the secret information can, however, be avoided if a defined event occurs before the maximum value of the counter is reached which automatically resets the counter state to its starting value. Any technical, economic or organisational condition can be defined as an event. Particular advantages of the invention presented are that each code can have its own counter allocated to it. In this way, different numbers of uses can be established for each code with regard to its function. As a chip card can contain any number of codes for the most widely differing applications, the block is limited solely to the application affected. The use of the chip card is not therefore blocked as a whole. The events can be easily adapted to the widest range of security and user requirements of the respective application area.