The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1999
Filed:
Oct. 17, 1995
Juhani Murto, Coppel, TX (US);
Nokia Telecommunications Oy, Espoo, FI;
Abstract
An authentication procedure in a Global System for Mobile Communications (GSM)-based mobile communications system relies on a challenge and response principle. A 32-bit Signed Response (SRES) parameter is calculated by an A3 algorithm from a 128-bit random number (RAND) and a 128-bit authentication key K.sub.i in a mobile station, and in an authentication center, and the SRES values are compared. A Cellular Authentication and Voice Encryption (CAVE) algorithm having a 152-bit input parameter and a 18-bit output parameter is employed as the A3 algorithm. Parameter adaptation functions are provided between the input parameter of the CAVE algorithm and the GSM-type input parameters, namely the random number RAND and the authentication key K.sub.i, as well as between the output parameter of the CAVE algorithm and the GSM output parameter, namely the signed response SRES.