Vehicle security device with electronic use authorization coding

US5708712A · kind A · utility

Assignee

• Mercedes-Benz Group AG · DE

Inventors

• Horst Brinkmeyer · Waiblingen, DE
• Michael Daiss · Echterdingen, DE
• Gunter Schwegler · Waiblingen, DE
• Bertolt Kruger · Bonn, DE

Key dates

• Filing date: Apr 3, 1995
• Grant date: Jan 13, 1998
• Expiry date: Apr 3, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2209/84
• WIPO field: Control
• WIPO sector: Instruments

Abstract

The invention provides a vehicle security device utilizing a rapid encryption method which operates on the basis of a "one-way function" and which requires storage in the vehicle of at most one item of secret coded information in a single piece of equipment, out of any desired number of pieces of equipment involved in vehicle security. In all such pieces of equipment only the one-way function values corresponding to inverse images stored in a key unit need to be present, the reading out of the said one-way function values making unauthorized manufacture of a copied key impossible. Security against interception and storage of information transmitted at the key end in order to produce copied keys is ensured by including an item of random information, transmitted at the vehicle end, in this authentication information.