Development of identity-based authenticated key agreement protocols : doctor of philosophy thesis

english

doktorska dela

2009

Univerza v Mariboru, Fakulteta za elektrotehniko računalništvo in informatiko

Key agreement protocols enable two or more entities to establish a shared session key which can be later used to achieve a cryptographic goal such as encryption of data sent over an insecure network. In addition, authenticated key agreement protocols assure authenticity of the participating entities. Different approaches can be used when developing authenticated key agreement protocols which affect their security and efficiency. Security of an authenticated key agreement protocol is defined using security attributes. Themain goal is to develop a protocol which is secure and efficient at the same time. This thesis discusses two-party and three-party identity-based authenticated key agreement protocols, their security and efficiency attributes and presents several contributions to the field. Firstly, two new two-party identity-based authenticated key agreement protocol using modular arithmetics are proposed, namely IDAK2-1 and IDAK2-2. Secondly, a key compromise impersonation attack on Scott's two-party identity-based authenticated key agreement protocol using pairings is described and two new two-party identity-based authenticated key agreement protocols which employ pairings are proposed - IDAK2P-1 and IDAK2P-2. Finally, two new three-party identity-based authenticated key agreement protocols which employ pairings areproposed, named IDAK3P-1 and IDAK3P-2. All proposed protocols are evaluatedregarding security and efficiency. The security comparison criterion is based upon the fulfillment of security attributes while the efficiency criterion is defined partly in scope of the thesis and partly from literature.It includes computational as well as communicational efficiency. Moreover, the proposed protocols are compared to existing ones with regard to efficiency and security. The security criterion is defined as the fulfillment of security attributes and the existence of attacks for a specific protocol. The efficiency comparison criterion is defined by the communicational and computation effort of each protocol. Additionally, a comprehensive in-depth review of existing two-party and three-party identity-based authenticated key agreement protocols, their properties and known attacks is given. The results of the thesis regarding two-party identity-based key agreement protocols using modular arithmetics indicate that IDAK2-1 and IDAK2-2 conform to all security attributes. IDAK2-2 is the most efficient protocol of the group equalto Saeednia et al's protocol, whereas IDAK2-1 is the second most efficient protocol of the group. Regarding two-party identity-based authenticated key agreement protocol employing pairing operations, both IDAK2P-1 and IDAK2P-2 offer all the security attributes, whereas several competitive protocols do not. IDAK2P-2 is among the most efficient protocols if pre-computations are taken into consideration, while IDAK2P-1 is more efficient than Choie-Jeong-Lee's protocol I. In the group of three-party identity-based authenticated key agreement protocols, the proposed IDAK3P-1 protocol conforms to all security attributes, whereas IDAK3P-2 lacks in perfect forward secrecy. However, specific competitive protocols share this deficiency. Regarding efficiency, IDAK3P-1 is the most efficient protocol, while IDAK3P-2 is the second most efficient and at the same level as Shim's protocol.

07.08.2023