Process for detecting unauthorized introduction of any data transmitted by a transmitter to a receiver

US5608800A · kind A · utility

Assignees

• Siemens Aktiengesellschaft · DE
• Siemens Nixdorf Informationssysteme AG · DE

Inventors

• Gerhard Hoffmann · Otterstadt, DE
• Klaus Lukas · Munich, DE
• Stephan Lechner · Hersbruck, DE
• Ferdinand Steiner · Hersbruck, DE
• Helmut Baumgartner · Ingolstadt, DE
• Ekkehard Lohmann · Bonn, DE
• Matthias Leclerc · Frankfurt, DE

Key dates

• Filing date: Oct 11, 1994
• Grant date: Mar 4, 1997
• Expiry date: Oct 11, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2209/34
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

The process is intended to establish whether the data transmitted by the transmitter (SE) to the receiver (EM) have been tapped and spuriously reintroduced at a later point in time and/or have been inadmissibly altered. For this purpose, the signature (S) assigned to the useful data (D) is enciphered symmetrically, using a combination of coupling data (K), characterizing the coupling between transmitter and receiver, and random data (Z), generated by a random generator. The coupling data are transmitted in plain text, the random data are enciphered. On the receiver side it can be established whether the transmitted message has been tapped and reintroduced at a later point in time if the coupling data are inadmissible. An alteration of the transmitted message can be established from ascertaining that the key used for enciphering the signature, obtained from the combination of coupling data and random data with the aid of a one-way function, does not correspond to the key obtained during deciphering at the receiver and consequently the deciphering of the enciphered signature leads to an incorrect result. The incorrect signature is detected during verification of the signature.