It is inevitable that transporting data security and private privacy protection in information technology are needed. Cryptographic algorithms and protocols are must-be-needed technologies to deploy the security in information technology society. Key management which contains generation, storing and distribution of keys is the fundamental component for securing the system. Security of the key is the most important barometer in security system. In this paper, we explain various attacks on the key establishment and provable security of key establishment protocols. In the end, we provide several key establishment protocols explicitly which are secure in the sense of provable security.
It is inevitable that transporting data security and private privacy protection in information technology are needed. Cryptographic algorithms and protocols are must-be-needed technologies to deploy the security in information technology society. Key management which contains generation, storing and distribution of keys is the fundamental component for securing the system. Security of the key is the most important barometer in security system. In this paper, we explain various attacks on the key establishment and provable security of key establishment protocols. In the end, we provide several key establishment protocols explicitly which are secure in the sense of provable security.
In this thesis we study the problem of secure key establishment, motivated by the construction of secure channels protocols to protect information transmitted over an open network. In the past, the purported security of a key establishment protocol was justified if it could be shown to withstand popular attack scenarios by heuristic analysis. Since this approach does not account for all possible attacks, the security guarantees are limited and often insufficient. \nThis thesis examines the provable security approach to the analysis of key establishment protocols. We present the security models and definitions developed in 2001 and 2002 by Canetti and Krawczyk, critique the appropriateness of the models, and provide several security proofs under the definitions. In addition, we consider the importance of the key compromise impersonation resilience property in the context of these models. We list some open problems that were encountered in the study.
For a secure communication through the public network, cryptographic encryption must be applied. The key establishment issue is the most important part in cryptographic encryption. Only the legitimate principals who have the key can encrypt messages and decrypt cryptograms. A secure multi-party communication held through the public network can only take place after a multi-party key establishment protocol has been executed. The multi-party key establishment protocol is designed so that the principals can receive a common key and use it to securely exchange the messages.\nIn this thesis, the secure multi-party key establishment protocols are discussed. W e start from investigating properties of two-party key establishment protocols such as motivation of using session key, adversaries in the protocols, attacks of the protocol and security analysis of the protocol. Then we give the requirements of a multi-party key establishment protocol and summarize about what should be considered in designing a multi-party key establishment protocol. After that we review some of the previous proposed multi-party key establishment protocol. The existing multi-party key establishment protocols are either impractical ( not efficient enough) or missing some important security goals such as authentication of principals. Three new protocols are proposed in this thesis. The first protocol addresses how to hold a conference for members of two hierarchical groups in an efficient way. The message broadcasting is used to reduce the cost of secure message transport.\nThe second and the third protocols manage the authentication problem by using a secret sharing scheme. We replace the principal authentication with the group authentication so that the computational overhead and communication overhead will be reduced especially in reuse of the protocol for new communication. Again, message broadcasting is used for replacing the expansive secure communication channel.\nPart of this thesis appeared in ACSC'99(Australian Computer Science Conference) and ACISP'99(Australian Conference of Information Security and Privacy).
Introduction/purpose: The problem of efficient distribution of cryptographic keys in communication systems has existed since its first days and is especially emphasized by the emergence of mass communication systems. Defining and implementing efficient protocols for symmetric cryptographic keys establishment in such circumstances is of great importance in raising information security in cyberspace. Methods: Using the methods of Information Theory and Secure Multiparty Computation, protocols for direct establishment of cryptographic keys between communication parties have been defined. Results: The paper defines two new approaches to the problem of establishing cryptographic keys. The novelty in the protocol defined in the security model based on information theory is based on the source of common randomness, which in this case is the EEG signal of each subject participating in the communication system. Experimental results show that the amount of information leaking to the attacker is close to zero. A novelty in the second case, which provides security with keys at the level of computer security by applying Secure Multiparty Computation, is in the new application field, namely generation and distribution of symmetric cryptographic keys. It is characteristic of both approaches that within the framework of formal theories, it is possible to draw conclusions about their security characteristics in a formal way. Conclusions: The paper describes two new approaches for establishing cryptographic keys in symmetric cryptographic systems with experimental results. The significance of the proposed solutions lies in the fact that they enable the establishment of secure communication between communication parties from end to end, avoiding the influence of a trusted third party. In that way, the achieved communication level security significantly increases in relation to classical cryptographic systems.
인터넷과 같은 첨단의 정보 전송 시스템이 발달함에 따라 네트워크 상에서 전송되는 메시지에 대한 기밀성을 제공하기 위해서 암호 시스템의 사용이 증가하고 있으며 그 중요성은 더욱 강조되고 있다. 안전한 암호 시스템을 구현하는 데 있어서 키 분배 프로토콜은 가장 필수적인 요소이며, 지금까지 여러 키 분배 프로토콜들이 표준으로 제안되었으나 이에 대한 엄밀한 안전성 증명은 아직까지 부족한 실정이다. 따라서 본 논문에서는 ANSI X9.42의 Diffie-Hellman형 표준 키 분배 프로토콜의 특징을 자세히 분석하고 이를 기반으로 여러 능동적 공격자 모델에 대한 프로토콜의 안전성을 증명하고자 한다 According to the wide-spread of information transmission system over network, the use of cryptographic system to provide the integrity of transmitted message over network is increasing and the importance of that is emphasized. Because the security of the cryptographic system totally relies on the key, key management is a essential part of cryptographic system. A number of key agreement protocols have been proposed to far, but their rigorous security analysis is still open. In this paper, we analyze the features of Diffie-Hellman based standard key agreement protocols and provide the security analysis of those protocols against several kinds of active attacks.
Introduction and motivation We live in time of computers and scientific and technological progress but this time is also marked with many attacks on big Internet companies. So with expand of Internet people start to protect information that they exchange through Internet. In the Internet world it is necessary for systems as Internet banking, Internet shopping or e-commerce to secure private information that are transferred via Internet. This necessity leads to design security improvements of existing protocols and to design and implement cryptographic algorithms (for example protocols as L2TP, Microsoft PPTP, IPSec, SSH or algorithms as DES, Blowfish and others). Consider that we have two banks, bank "Alice" and bank "Bob" and these two banks for business purposes need the private cipher for their communication. They need this cipher to do secret bank operation. So they need the secure way, how to arrange the cip
Recent advances in quantum technology and the potential that practical quantum computers may become a reality in the future have led to renewed interest in developing cryptographic technologies that are secure against conventional and quantum attacks. Currently, virtually all asymmetric cryptographic schemes in use are threatened by the potential development of powerful quantum computers. Post-quantum cryptography is one of main the ways to combat this threat. Its security is based on the complexity of mathematical problems that are currently considered unsolvable efficiently, even with the help of quantum computers. The security of information systems is ensured through protection against various threats that use system vulnerabilities. Security protocols are the building blocks of secure communication. They implement security mechanisms to provide security services. Security protocols are considered abstract when analyzed, but may have additional vulnerabilities in implementation. This work contains a holistic study of security protocols. Basics of security protocols, taxonomy of attacks on security protocols and their implementation are considered, as well as various methods and models of protocol security analysis. In particular, the differences between information-theoretic and computational security, computational and symbolic models are specified. In addition, an overview of the computational security models for Authenticated Key Exchange (AKE) and Password Authentication Key Exchange (PAKE) protocols is provided. The most important security models for the AKE and PAKE protocols were also described. With the emergence of new technologies that may have different security requirements, as well as with increased opportunities for competition, there is always a need to develop new protocols. Thus, the purpose of this article is to review, classify, analyze, and research the vulnerabilities of information systems from classical, quantum, and special attacks, performed taking into account the forecast regarding the possibilities of attacks on post-quantum cryptographic transformations; studying security assessment models for existing cryptographic protocols, as well as reviewing and benchmarking security models and providing suggestions for protection against existing potential attacks.