Search International and National Patent Collections
Some content of this application is unavailable at the moment.
If this situation persists, please contact us atFeedback&Contact
1. (WO1991009484) A SECURITY CIRCUIT FOR MOBILE RADIO TELEPHONES AS WELL AS A METHOD TO BE USED IN CONNECTION WITH THE CIRCUIT
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1991/009484 International Application No.: PCT/DK1990/000326
Publication Date: 27.06.1991 International Filing Date: 11.12.1990
Chapter 2 Demand Filed: 04.06.1991
IPC:
H04W 88/02 (2009.01)
H ELECTRICITY
04
ELECTRIC COMMUNICATION TECHNIQUE
W
WIRELESS COMMUNICATION NETWORKS
88
Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
02
Terminal devices
Applicants:
CETELCO CELLULAR TELEPHONE COMPANY A/S [DK/DK]; Østre Allé 6 DK-9530 Støvring, DK (AllExceptUS)
JAKOBSEN, Jens [DK/DK]; DK (UsOnly)
DAHL, Bent [DK/DK]; DK (UsOnly)
Inventors:
JAKOBSEN, Jens; DK
DAHL, Bent; DK
Agent:
CHAS. HUDE; H.C. Andersens Boulevard 33 DK-1553 Copenhagen V, DK
Priority Data:
6244/8911.12.1989DK
Title (EN) A SECURITY CIRCUIT FOR MOBILE RADIO TELEPHONES AS WELL AS A METHOD TO BE USED IN CONNECTION WITH THE CIRCUIT
(FR) CIRCUIT DE SECURITE POUR APPAREIL RADIOTELEPHONIQUE MOBILE ET PROCEDE UTILISE CONJOINTEMENT AVEC LE CIRCUIT
Abstract:
(EN) A security circuit for an NMT-mobile radio telephone using SIS (Subscribers Identity Security) comprising a single chip with a CPU and associated memories, wherein the memories storing the authentication key (SAK) for the SIS are divided into accessible areas (202, 206, 208, 222) and nonaccessible areas (220, 204), to which access is allowed only by CPU instructions fetched from a ROM (202) containing internal code enabling reading of the SAK in the secret areas (204), when a call from a subscriber is processed. The new circuit renders it possible to maintain the secrecy of the SAK even though the CPU is connected to external data equipment (130, 140).
(FR) Circuit de sécurité pour appareil radiotéléphonique mobile NMT, utilisant un système SIS (sécurité d'identité d'abonnés) comprenant une seule puce dotée d'une unité centrale et de mémoires associées, dans lequel les mémoires stockant le code d'authentification (CA) pour le système SIS, sont divisées en zones accessibles (202, 206, 208, 222) et en zones non accessibles (220, 204), auxquelles l'accès est permis uniquement à l'aide d'instructions de l'unité centrale extraites d'une mémoire morte (202) contenant un code interne validant la lecture du code d'authentification dans les zones secrètes (204), lorsqu'un appel d'un abonné est traité. Le nouveau circuit permet de maintenir le secret du code d'authentification même si l'unité centrale est connectée à un équipement extérieur de données (130, 140).
Designated States: AT, AU, BB, BG, BR, CA, CH, DE, DK, ES, FI, GB, GR, HU, JP, KP, KR, LK, LU, MC, MG, MW, NL, NO, RO, SD, SE, SU, US
European Patent Office (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL, SE)
African Intellectual Property Organization (BF, BJ, CF, CG, CM, GA, ML, MR, SN, TD, TG)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
AU1991070383