Method of distributing a public key

• US 20050069137A1
• Filed: 12/10/2002
• Published: 03/31/2005
• Est. Priority Date: 12/10/2001
• Status: Active Grant

• Current Assignee: Cryptomathic A/S (Infineon Technologies AG)
• Original Assignee: Cryptomathic A/S (Infineon Technologies AG)
• Inventors: Landrock, Peter
• Granted Patent: US 7,362,869 B2
• Time in Patent Office: Days
• US Class Current: 380/278
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 2463/081 applying self-generating credentials, e.g. instead of receiving credentials from an authority or from another peer, the credentials are generated at the entity itself cryptographic mechanisms or cryptographic arrangements for generation of secret information including derivation or calculation of cryptographic keys or passwords H04L9/0861
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/0838 using one-time-passwords
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04L 9/0863 involving passwords or one-time passwords network architectures or network communication protocols for using one-time keys in a packet data network H04L63/067
• CPC Class Codes: H04L 9/0897 involving additional devices, e.g. trusted platform module [TPM], smartcard or USB
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/06 Authentication

Abstract

A method of distributing the public key of an asymmetric key pair with a private key and the public key from a mobile station to a key managing computer, the method comprising the steps of: communicating a password (OTP) from the key managing (203) computer to the mobile station (209) of a registered user (201) by means of a secure channel (202) to thereby provide a shared secret; at the mobile station and at the key managing computer, generating a first code (MAC1) and a second code (MACT1), respectively, based on the same predefined generation method, which codes (MAC1; MACT1) are generated from the password (OTP); by means of the mobile station (209), transmitting the public key and the first code (MAC1) to the key managing computer (203); at the key managing computer (203), receiving the public key and the first code (MAC1) from the mobile station (209); checking the authenticity of the registered user (201) based on comparing the first code (MAC1) and the second code (MAC1).

Claims

1. A method of distributing the public key of an asymmetric key pair with a private key and the public key from a mobile station to a key managing computer, the method comprising the steps of:

communicating a password (OTP) from the key managing (203) computer to the mobile station (209) of a registered user (201) by means of a secure channel (202) to thereby provide a shared secret;

at the mobile station and at the key managing computer, generating a first code (MAC1) and a second code (MACT1), respectively, based on the same predefined generation method, which codes (MAC1;

MACT1) are generated from the password (OTP);

by means of the mobile station (209), transmitting the public key and the first code (MAC1) to the key managing computer (203);

at the key managing computer (203), receiving the public key and the first code (MAC1) from the mobile station (209);

checking the authenticity of the registered user (201) based on comparing the first code (MAC1) and the second code (MACT1).

2. A method according to claim 1, wherein said first and second codes (MAC1;

MACT1) are generated from the password (OTP) in combination with the said public key as a Message Authentication Code.

3. A method according to claim 1, wherein said asymmetric key pair is generated by said mobile station (209), and the generation of said asymmetric key pair is initiated by the password (OTP) being entered into the mobile station (209).

4. A method according to claim 3, wherein a user authentication is attached to the private key during generation of said asymmetric key pair, where the user authentication must be entered when the private key is to be accessed (i.e. used).

5. A method according to claim 1, wherein the predefined generation method comprises the following steps:

generating a string at least comprising said password (OTP); and

hashing the string using a predefined hashing function.

6. A method according to claim 5, wherein the predefined hashing function is a secure hash algorithm, such as SHA-1.

7. A method according to claim 1, further comprising the step of:

if, by comparing the first code (MAC1) and the second code (MACT1), a match is found, the registered user (201) is authenticated and a further code (MAC2), which is generated from a second public key in a second asymmetric key pair of the key managing computer (203) and the password (OTP), is transmitted to the mobile station (209).

8. A method according to claim 7, further comprising the step of:

at the mobile station (209) generating a temporary code (MACT2) based on the second public key and the password (OTP) by means of the predefined generation method;

comparing the further code (MAC2) and the temporary code (MACT2);

if, by comparing the further code (MAC2) and the temporary code (MACT2), a match is found, the mobile station (209) accepts the second public key for subsequent secure communication with the key managing computer.

9. A method according to claim 1, wherein the secure channel (202) is a channel where the mobile station (209) and the key managing computer (203) are authenticated to each other.

10. A method according to claim 1, wherein the mobile station (209) comprises a smart card and wherein the private key is generated and stored at a first application on the smart card and wherein the first code (MAC1) is generated at a second application at the smart card.

11. A method according to claim 10, wherein the smart card is a Subscriber Identity Module (SIM card).

12. A method according to claim 1, wherein the key managing computer (203) represents at least one financial institute, such as a bank, and the mobile station is registered to a costumer with an account in said at least one financial institute.

13. A method according to claim 1, wherein the communication between the mobile station (209) and the key managing computer (203) is performed by a cellular network.

22. An application module according to claim 1, configured to:

receive the password and a further code, which is generated from a second public key in a second asymmetric key pair of the key managing computer;

generate a temporary code based on the received public key, which is received from the specified key managing computer, and the password by means of the predefined generation method;

compare the further code and the temporary code;

if, by comparing the further code and the temporary code, a match is found, the mobile station accepts the second public key for subsequent secure communication with the key managing computer.

14. An application module arranged on a smart card, which is registered to a user for use of the smart card in a mobile station;

and wherein the application module is configured to

receive a password entered by the user, and to

generate and store an asymmetric key pair with a public key and a private key

characterized in that the application module further is configured to;

generate a first code based on the same predefined generation method as is used for generating a second code at a specified key managing computer, which first and second codes are generated from the password as a Message Authentication Code;

via the mobile station, transmit the public key and the first code to the specified key managing computer to enable authentication of the registered user'"'"'s public key, based on comparing the first and second code.

15. An application module according to claim 14, configured to:

generate the private key and the public key;

generate the code; and

perform encryption and/or decryption operations of messages based on the private and/or public key.

16. An application module according to claim 14, wherein the generation of the private key involves identification information (OTP) transmitted via a pre-established secure channel over the Internet, and where the OTP is entered into the mobile station via a keypad of the mobile station.

17. An application module according to claim 14, wherein said first and second codes are generated from the password in combination with the public key.

18. An application module according to claim 14, wherein said asymmetric key pair is generated by said mobile station, and the generation of said asymmetric key pair is initiated by the password being entered into the mobile station.

19. An application module according to claim 14, wherein a user authentication is attached to the private key during generation of said asymmetric key pair, where the user authentication must be entered when the private key is to be accessed (i.e. used).

20. An application module according to claim 14, wherein the predefined generation method comprises the following steps,

generating a string at least comprising said password,

hashing the string using a predefined hashing function.

21. An application module according to claim 20, wherein the predefined hashing function is a secure hash algorithm, such as SHA-1.