Voice network security system

• US 4,797,672 A
• Filed: 09/04/1986
• Issued: 01/10/1989
• Est. Priority Date: 09/04/1986
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Octel Communications Corp. (Nokia Corporation)
• Inventors: Kousa, Paavo T.
• Primary Examiner(s): YUSKO, DONALD
• Application Number:
  US06/904,085
• Time in Patent Office: 859 Days
• Field of Search: 340/825.3, 340/825.31, 340/825.33, 340/825.34, 380/42-48
• US Class Current: 340/5.26
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys

Abstract

A voice network security system is disclosed which provides improved security aspects in transmitting voice messages between remote locations for use in a business environment. The security aspects of the present invention serve to prevent unauthorized access to the transmitted messages.

A microfiche appendix (A) of one microfiche and 41 frames is included as part of the specification (3 CFR 1.96b).

Claims

1. A communication security system comprising

a base station,

one or more node stations,

means for transmitting a first signal from said base station to a first one of said node stations,

said first node station responsive to said first signal for transmitting a second response signal to said base station,

said base station responsive to said second response signal for generating a node encryption key which includes a node identification number of said first node station and an arbitrary number,

said base station further including means for generating a first random number, means for encrypting said first random number with said node encryption key, and means for transmitting said first encrypted random number to said first node station,

said first node station including means for decrypting said encrypted random number to recover said first random number to act as a seed for subsequent encrypted transmissions to said base station, means for generating a second random number, means for encrypting said second random number with an encoding key based upon said decoded first random number to form a second encrypted random number, and means for transmitting said second encrypted number to said base station,

said base station including means for decoding said transmitted second encrypted number to recover said second random number to act as a seed for subsequent encrypted transmissions to said first node station.

2. In a voice network security system including a base station, one or more node stations, means for transmitting a first signal from said base station to a first one of said node station, said first node station responsive to said first signal for transmitting a second response signal to said base station, the method comprising the steps of

generating in response to said second response signal a node encryption key which includes a node identification number of said first node station and an arbitrary number,

generating a first random number, encrypting said first random number with said node encryption key,

transmitting said first encrypted random number to said first node station,

decrypting said encrypted random number to recover said first random number to act as a seed for subsequent encrypted transmissions to said base station, generating a second random number, encrypting said second random number with an encoding key based upon said decoded first random number to form a second encrypted random number, transmitting said second encrypted number to said base station, and

decoding said transmitted second encrypted number to recover said second random number to act as a seed for subsequent encrypted transmissions to said first node station.

3. A voice network security system comprising

a base station,

one or more node stations,

said base station including means for generating a node encryption key which includes a node identification number of a first one of said node stations and an arbitrary number,

said base station further including means for generating a first random number, means for encrypting said first random number with said node encryption key, and means for transmitting said first encrypted random number to said first node station,

said first node station including means for decrypting said encrypted random number to recover said first random number to act as a seed for subsequent encrypted transmissions to said first base station, means for generating a second random number, means for encrypting said second random number with an encoding key based upon said decrypted first random number to form a second encrypted random number, and means for transmitting said second encrypted number to said base station,

said base station including means for decoding said transmitted second encrypted number to recover said second random number to act as a seed for subsequent encrypted transmissions to said first node station.