4,633 research outputs found

    Fast, parallel and secure cryptography algorithm using Lorenz's attractor

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    A novel cryptography method based on the Lorenz's attractor chaotic system is presented. The proposed algorithm is secure and fast, making it practical for general use. We introduce the chaotic operation mode, which provides an interaction among the password, message and a chaotic system. It ensures that the algorithm yields a secure codification, even if the nature of the chaotic system is known. The algorithm has been implemented in two versions: one sequential and slow and the other, parallel and fast. Our algorithm assures the integrity of the ciphertext (we know if it has been altered, which is not assured by traditional algorithms) and consequently its authenticity. Numerical experiments are presented, discussed and show the behavior of the method in terms of security and performance. The fast version of the algorithm has a performance comparable to AES, a popular cryptography program used commercially nowadays, but it is more secure, which makes it immediately suitable for general purpose cryptography applications. An internet page has been set up, which enables the readers to test the algorithm and also to try to break into the cipher in

    Formal security analysis of registration protocols for interactive systems: a methodology and a case of study

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    In this work we present and formally analyze CHAT-SRP (CHAos based Tickets-Secure Registration Protocol), a protocol to provide interactive and collaborative platforms with a cryptographically robust solution to classical security issues. Namely, we focus on the secrecy and authenticity properties while keeping a high usability. In this sense, users are forced to blindly trust the system administrators and developers. Moreover, as far as we know, the use of formal methodologies for the verification of security properties of communication protocols isn't yet a common practice. We propose here a methodology to fill this gap, i.e., to analyse both the security of the proposed protocol and the pertinence of the underlying premises. In this concern, we propose the definition and formal evaluation of a protocol for the distribution of digital identities. Once distributed, these identities can be used to verify integrity and source of information. We base our security analysis on tools for automatic verification of security protocols widely accepted by the scientific community, and on the principles they are based upon. In addition, it is assumed perfect cryptographic primitives in order to focus the analysis on the exchange of protocol messages. The main property of our protocol is the incorporation of tickets, created using digests of chaos based nonces (numbers used only once) and users' personal data. Combined with a multichannel authentication scheme with some previous knowledge, these tickets provide security during the whole protocol by univocally linking each registering user with a single request. [..]Comment: 32 pages, 7 figures, 8 listings, 1 tabl

    Efficient two-stage cryptography scheme for secure distributed data storage in cloud computing

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    Cloud computing environment requires secure access for data from the cloud server, small execution time, and low time complexity. Existing traditional cryptography algorithms are not suitable for cloud storage. In this paper, an efficient two-stage cryptography scheme is proposed to access and store data into cloud safely. It comprises both user authentication and encryption processes. First, a two-factor authentication scheme one-time password is proposed. It overcomes the weaknesses in the existing authentication schemes. The proposed authentication method does not require specific extra hardware or additional processing time to identity the user. Second, the plaintext is divided into two parts which are encrypted separately using a unique key for each. This division increases the security of the proposed scheme and in addition decreases the encryption time. The keys are generated using logistic chaos model theory. Chaos equation generates different values of keys which are very sensitive to initial condition and control parameter values entered by the user. This scheme achieves high-security level by introducing different security processes with different stages. The simulation results demonstrate that the proposed scheme reduces the size of the ciphertext and both encryption and decryption times than competing schemes without adding any complexity

    Securing One Time Password (OTP) for Multi-Factor Out-of-Band Authentication through a 128-bit Blowfish Algorithm

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    Authentication and cryptography have been used to address security issues on various online services. However, researchers discovered that even the most commonly used multi-factor out-of-band authentication mechanism was vulnerable to attacks and traditional crypto-algorithms were characterized to have some drawbacks making it crucial to choose desirable algorithms for a particular purpose. This study introduces an innovative modification of the Blowfish algorithm designed to capitalize on its strengths but supports 128-bits block size text input using dynamic selection encryption method and reduction of cipher function execution through randomly determined rounds. Experimentation results on 128-bit input text revealed significant performance improvements with utmost 5.91 % in terms of avalanche effect, 38.97 % for integrity, and 41.02 % in terms of execution time. Results also showed that the modification introduced extra security layer, thus, displaying higher complexity and stronger diffusion at faster execution time making it more difficult and complex for an unauthorized individual to decipher the information and desirable to be used for applications with multiple users respectively. This is a good contribution to the continuous developments in the field of information security particularly in cryptography and towards providing a secure OTP for multifactor out-of-band authentication
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