METHOD OF AUTHENTICATION AND SESSION KEY AGREEMENT FOR SECURE DATA TRANSMISSION, A METHOD FOR SECURELY TRANSMITTING DATA, AND AN ELECTRONIC DATA TRANSMISSION SYSTEM

• US 20120082312A1
• Filed: 10/04/2011
• Published: 04/05/2012
• Est. Priority Date: 10/05/2010
• Status: Active Grant

• Current Assignee: Brandenburgische Technische Universitã¤T Cottbus
• Original Assignee: Brandenburgische Technische Universitaet Cottbus- Senftenberg
• Inventors: Liu, Fuwen, König, Hartmut
• Granted Patent: US 8,443,194 B2
• Time in Patent Office: Days
• US Class Current: 380/262
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• 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

Abstract

The invention relates to a method of authentication and session key agreement for secure data transmission between a first and second data communication entity in an electronic data transmission system. Furthermore, the invention relates to an electronic transmission system to perform a method of authentication and session key agreement.

Claims

1. A method of authentication and session key agreement for secure data transmission between a first data communication entity and a second data communication entity in an electronic data transmission system, the method comprising:

in a commitment phase in both the first data communication entity and the second data communication entity, providing a password pw, and parameters g, p, and q with G={g^r mod p;

1≦

r<

p}, where G is a finite cyclic group with a large prime order p, g is a primitive root modulo p in G so that, for any xY [1, p−

1], there always exists a value r to meet the formula g^r mod p=x;

in the first data communication entity,

generating a first symmetric encryption key by applying a hash function to the password;

pwa=H(pw |ID_a), wherein ID_a is an identity of a first user using the first data communication entity;

generating a first temporary private key r_aε

_R [1,p−

1] and a first shadow private key s_aε

_R[1, 2<sup>L−

1</sup>], where L is a block size of an encryption algorithm;

generating a first temporary public key t_a=g^ra and a first shadow public u_a=g^sa;

generating a first modular sum;

W_a=t_a+u_a;

encrypting the first shadow private key with the first symmetric encryption key using the encryption algorithm;

ES_a=E_pwa{s_a}; and

transmitting the identity of the first user, the first modular sum, and the encrypted first shadow private key from the first data communication entity to the second data communication entity over a communication channel provided in the electronic data transmission system;

in the second data communication entity,

generating a second symmetric encryption key by applying the hash function to the password;

pwb=H(pw | ID_b), wherein ID_b is an identity of a second user using the second data communication entity;

generating a second temporary private key r_bε

_R [1,p−

1] and a second shadow private key s_bε

_R[1, 2<sup>L−

1</sup>], where L is a block size of the encryption algorithm;

generating a second temporary public key t_b=g^rb and a second shadow public u_b=g^sb;

generating a second modular sum;

W_b=t_b+u_b;

encrypting the second shadow private key with the second symmetric encryption key using an AES encryption;

ES_b=E_pwb{s_b}; and

transmitting the identity of the second user, the second modular sum, and the encrypted second shadow private key from the second data communication entity to the first data communication entity over the communication channel provided in the electronic data transmission system; and

in a confirmation phase,

in the first data communication entity,

if for the second modular sum W_b≠

0, decrypting the second shadow private key by using the second symmetric encryption key;

s_b=D_pwb{ES_b};

generating a first confirmation key by using the following formula;

CK_a=(W_b−

g^sb)_ra=g^rbra;

generating a first verification tag;

V_a=H(CK_a | ID_a | ID_b | W_a | W_b | ES_a | ES_b | pwa |

     0); and

transmitting the first verification tag from the first data communication entity to the second data communication entity over the communication channel provided in the electronic data transmission system, and

in the second data communication entity,

verifying the first verification tag;

decrypting the first shadow private key by using the first temporary private key;

s_a=D_pwa{ES_a};

generating a second confirm key by using the following formula;

CK_b=(W_a−

g^sa)^rb=g^rarb;

generating a second verification tag;

V_b=H(CK_b | ID_a | ID_b | W_a | W_b | ES_a | ES_b | pwb |

     1); and

transmitting the second verification tag from the second data communication entity to the first data communication entity over the communication channel provided in the electronic data transmission system, and

in the first data communication entity, verifying the second verification tag; and

generating a shared session key in the first and second data communication entity;

SK=H(CK_a | ID_a | ID_b | W_a | W_b |1 ES_a | ES_b) and SK=H(CK_b | ID_a | ID_b | W_a | W_b | ES_a | ES_b).

2. The method according to claim 1, wherein the encryption algorithm is an AES encryption.

3. The method according to claim 1, wherein in the electronic data transmission system, data are exchanged over a wireless data connection between the first data communication entity and the second data communication entity.

4. A method of securely transmitting electronic data between a first data communication entity and a second data communication entity in an electronic data transmission system, the method comprising:

providing a data transmission channel between the first data communication entity and the second data communication entity in the electronic data transmission system,

performing an authentication and a session key agreement for secure data transmission between the first data communication entity and the second data communication entity according to the method of claim 1; and

transmitting electronic data between the first data communication entity and the second data communication entity using a shared session key in the first and second data communication entities.

5. An electronic data transmission system, comprising:

a first data communication entity;

a second data communication entity; and

a data transmission channel connecting the first a data communication entity and the second data communication entity;

wherein the first data communication entity and the second data communication entity are configured, by at least one of software and hardware modules, to perform an authentication and a session key agreement for secure data transmission according to the method in claim 1.