Authentication process including setting up a secure channel between a subscriber and a service provider accessible through a telecommunications operator

• US 6,745,326 B1
• Filed: 01/24/2000
• Issued: 06/01/2004
• Est. Priority Date: 01/22/1999
• Status: Expired due to Term

• Current Assignee: Societe Francaise De Radiotelephone SA (Altice Europe NV)
• Original Assignee: Societe Francaise De Radiotelephone SA (Altice Europe NV)
• Inventors: Wary, M. Jean-Philippe
• Primary Examiner(s): Barron, Gilberto
• Assistant Examiner(s): Dinh, Minh
• Application Number:
  US09/489,952
• Time in Patent Office: 1,590 Days
• Field of Search: 709/226, 713/168-175, 455/410, 455/411, 455/433, 380/247-249
• US Class Current: 713/168
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 12/068 using credential vaults, e.g. password manager applications or one time password [OTP] applications

Abstract

Security through data transfers through one or several telecommunications networks is accomplished by providing a data transfer process through a secure channel that enables a subscriber and a service provider to communicate in the secure manner without any action by, or even unknown to, the subscriber'"'"'s attachment network operator. The process is characterized in that it comprises firstly a process for initial registration of the said subscriber with the service provider through the operator, and secondly a process in which each of the communication sessions between the subscriber and the service provider are executed, the initial registration process consisting of an exchange of authentication data (DeviceID, R1; Login, mdp) online or off line, and the encrypted channel may then be setup at the beginning of each session after mutual authentication involving cryptographic functions, and then calculation of an encryption key Kses without transmission of a secret element on the network(s).

Claims

1. Process for ensuring the security of a communications between firstly a subscriber to a telecommunications network and secondly a service provider accessible through an operator of the telecommunications network to which the subscriber is attached,

characterized in that it comprises firstly a process for initial registration of the subscriber to the service provider through the operator, and secondly a process in which each of the communication sessions between the subscriber and the service provider takes place,

and in that the initial registration process comprises:

firstly, the telecommunications operator provides the service provider with

an identifier (Device ID) of the subscriber in his attachment network, and

an authenticator (R1) of the subscriber composed of a first numeric value calculated from an identifier (Idx) of the service provider in the operator'"'"'s network, the identifier (Device ID) of the subscriber in his attachment network, and a secret element (Sec. Op.) characterizing the subscriber;

secondly, the service provider provides the subscriber with data for identification/authentication (Login, mdp) of the subscriber with the service provider;

and in that the execution process of each of the sessions comprises authentication of the subscriber by the service provider through the following steps;

a step in which a second numeric value (R2) is calculated from a subscriber identifier (mdp) with the service provider and a diversification data (Date) generated at the subscriber

a step in which a third numeric value (R3) is calculated starting from the first numeric value (R1), the second numeric value (R2) and a third data (Login) identifying the subscriber with the service provider,

a step in which a first data frame composed of the third numeric value (R3) and input data, namely data (Login) identifying the subscriber with the service provider, and the diversification data (Date) generated at the subscriber, is transmitted from the subscriber to the service provider,

a step in which the service provider authenticates the subscriber by recalculating, as a validation, the third numeric value (R3) starting from the input data (Login, Date) in the first data frame, and data (R1, mdp) already provided to the service provider and associated with the subscriber.

2. Process according to claim 1, characterized in that it also comprises authentication of the service provider by the subscriber by means of the following steps:

a step in which a fourth numeric value (R4) is calculated starting from the subscriber authenticator (R1), a random variable (Random) generated at the service provider and diversification data (Date);

a step in which a second data frame composed of the fourth numeric value (R4) and the random variable (Random), is transmitted from the service provider to the subscriber;

a step in which the subscriber authenticates the service provider by a recalculation, as a validation of the fourth numeric value (R4) starting from the random variable (Random) in the second data frame, and data (R1, Date) provided to the subscriber.

3. Process according to claim 1, characterized in that it also comprises:

a phase in which a session key (Kses) common to the subscriber and the service provider is generated; and

,

a phase in which the encrypted data are transmitted by means of the session key (Kses); and

in that the phase in which a session key (Kses) is generated preferably comprises the following steps;

a step in which the service provider calculates a session key (Kses) starting from calculation data comprising the second numeric value (R2) and a random variable (Random2);

a step in which the single random variable (Random2) is transmitted to the subscriber;

a step in which the subscriber calculates the session key starting from the calculation data, namely from the transmitted random variable (Random2) and the second numeric value (R2) provided to the subscriber.

4. Process according to claim 2, characterized in that the random variables Random and Random2 are identical, and in that the phase for creation of a session key (Kses) does not comprise any data transmission from the service provider to the subscriber, and random variable already being available to the subscriber by means of the second data frame.

5. Process according to claim 3, characterized in that the calculation data for the session key (Kses) also include the authenticator of the subscriber (R1), the authenticator (R1) being provided both to the service provider and to the subscriber without the need for it to be transmitted from the service provider to the subscriber, and in that if the calculated session key (Kses) is obtained correctly, the service provider is effectively authenticated by the subscriber due to the fact that the encrypted data received from the service provider and decrypted by means of the session key (Kses) calculated by the subscriber are intelligible.

6. Process according to claim 1, characterized in that the calculation data for the session key (Kses) also include the diversification data (Date), the diversification data (Date) being provided both to the service provider and the subscriber without the need for it to be transmitted from the service provider to the subscriber.

7. Process according to claim 1, characterized in that the service provider builds up a database associating the following items of data with each registered subscriber:

an identifier (DeviceID) for the subscriber in his attachment network;

subscriber identification/authentication data with the service provider (Login,mdp);

the numeric value R1 received from the operator at the time of the initial registration process;

possibly, some of all of the values Date, R3, Random, Random2 and Kses specific to the current communication session.

8. Process according to claim 1, characterized in that at least some of the first, second, third and fourth numeric values of R1, R2, R3 and R4 are the session key Kses are calculated using a cryptographic algorithm f1, f2, f3, f4, fk.

9. Process according to claim 8, characterized in that the first numeric value R1 is calculated using an A3/A8 type algorithm f1.

10. Process according to claim 8, characterized in that the cryptographic algorithm belongs to the group containing:

algorithms with a single-directional chopping function with a key, such as DES in MAC mode;

algorithms with a single-directional chopping function without a key, such as md5 (registered trademark), RIPEM and SHA;

algorithms with bit mixing.

11. Process according to claim 1, characterized in that the secret element (Sec. Op.) characterizing the subscriber belongs to the group containing the key Ki contained in the SIM card of the subscriber'"'"'s mobile and an arbitrary key Kkm available in the subscriber'"'"'s terminal.

12. Process according to claim 1, characterized in that when the subscriber is attached to the GSM network, the subscriber'"'"'s identifier (Device ID) in his attachment network advantageously belongs to the group including the IMSI (International Mobile Subscriber Identity) and the MSISDN (Mobile Station ISDN number).

13. Process according to claim 1, characterized in that the identification/authentication data (Login, mdp) of the subscriber with the service provider comprise:

a subscriber identifier (Login) in the service provider'"'"'s network;

a secret element (mdp) supplied to the subscriber by the service provider.

14. Process according to claim 1, characterized in that the diversification data (Date) used to calculate a second numeric value (R2) belongs to the group comprising the date and/or time of the session, a number incremented in each new session requested by the subscriber, and a random number generated at the subscriber.

15. Process according to claim 1, characterized in that the first numeric value (R1) forming the authenticator of the subscriber is generated during each session and is not kept by the subscriber.

16. Process according to claim 1, characterized in that at least some of the data (Device ID, R1;

Login, mdp) exchanged during the initial registration phase of the subscriber with the service provider are transmitted using a means comprising online transmissions and off line transmissions.

17. Process according to claim 1, characterized in that the second numeric value (R2) is simply equal to the secret element (mdp) supplied by the service provider to the subscriber.