U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Cryptographic key management method and apparatus

Patent 5375169 Issued on December 20, 1994. Estimated Expiration Date: Icon_subject May 28, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Patent References

Public key cryptographic apparatus and method
Patent #: 4218582
Issued on: 08/19/1980
Inventor: Hellman ,   et al.

Cryptographic communications system and method
Patent #: 4405829
Issued on: 09/20/1983
Inventor: Rivest ,   et al.

Cryptographic key sharing circuit and method using code correction
Patent #: 4417338
Issued on: 11/22/1983
Inventor: Davida

Exponentiation cryptographic apparatus and method
Patent #: 4424414
Issued on: 01/03/1984
Inventor: Hellman ,   et al.

Method for establishing user authenication with composite session keys among cryptographically communicating nodes
Patent #: 4649233
Issued on: 03/10/1987
Inventor: Bass ,   et al.

Controlled use of cryptographic keys via generating station established control values
Patent #: 4850017
Issued on: 07/18/1989
Inventor: Matyas, Jr. ,   et al.

Key distribution method
Patent #: 4876716
Issued on: 10/24/1989
Inventor: Okamoto

Mobile communication system
Patent #: 4955082
Issued on: 09/04/1990
Inventor: Hattori, et al.

Cryptographic communication method and cryptographic communication device
Patent #: 5136642
Issued on: 08/04/1992
Inventor: Kawamura, et al.

Cryptographic system allowing encrypted communication between users with a secure mutual cipher key determined without user interaction Patent #: 5150411
Issued on: 09/22/1992
Inventor: Maurer

Inventors

Application

No. 069577 filed on 05/28/1993

US Classes:

713/171, Having key exchange380/2, EQUIPMENT TEST OR MALFUNCTION INDICATION380/28, PARTICULAR ALGORITHMIC FUNCTION ENCODING380/46, Nonlinear (e.g., pseudorandom)380/283, User-to-user key distributed over data link (i.e., no center)713/181Message digest travels with message

Examiners

Primary: Gregory, Bernarr E.

Attorney, Agent or Firm

International Classes

H04L 009/08
H04L 009/28

Abstract

A system for the secure communication of a message from a transmitting user to a receiving user using a split key scheme. Each user generates a key component using a cryptographic engine. The key component is a pseudorandom sequence of bits with an appended error detection field which is mathematically calculated based on the pseudorandom sequence. This key component is then sent out on a communications channel from the transmitting user to the receiving user. The receiving user also sends its key component to the transmitting user. Each location performs a mathematical check on the key component received from the other location. If the key component checks pass at both locations, the transmit key component and the receive key component, including the error detection fields, are combined at both locations, forming identical complete keys at both locations. The identical complete keys are then used to initiate the cryptographic engines at both locations for subsequent encryption and decryption of messages between the two locations.

Other References

  • Massey, An Introduction to Contemporary Cryptology, May 1988; "Proc,s of the IEEE"; vol. 76, No. 5; pp. 533-549
  • Schneier, Untangling Public-Key Cryptography, May 1992; "Dr. Dobb's Journal", pp. 16-2
PatentsPlus Images
Enhanced PDF formats
loading...
PatentsPlus: add to cart
PatentsPlus: add to cartSearch-enhanced full patent PDF image
$9.95more info
PatentsPlus: add to cart
PatentsPlus: add to cartIntelligent turbocharged patent PDFs with marked up images
$16.95more info
 
Sign InRegister
Username  
Password   
forgot password?