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Security and privacy issues of blockchain-enabled fog and edge computing
Published in Muhammad Maaz Rehan, Mubashir Husain Rehmani, Blockchain-enabled Fog and Edge Computing, 2020
Imane Ameli, Nabil Benamar, Abdelhakim Senhaji Hafid
Cryptographic hashing [33] is a mechanism used to encrypt data transactions before broadcasting it in the network by its issuer. Secure hash algorithm (SHA256) is the famous hash algorithm implemented in several cryptosystems which relies on hashing an input parameter and converting it to an output with a size of 256 bit. It is a one-way function; that is, each input has one and only hash target as a result, and also there is no way to predict and to divine the input just based on the hash. Additionally, SHA-256d (SHA256 function is applied two times on data) is used for enhancing the complexity and the mining time (Bitcoin, Peercoin implement the SHA-256d). Also Scrypt (implemented by Litecoin) and EtHash (implemented by Ethereum) are other algorithms as a hashing function [34].
Privacy-Preserving Anonymous Secure Communication in Pervasive Computing
Published in Syed Ijlal Ali Shah, Mohammad Ilyas, Hussein T. Mouftah, Pervasive Communications Handbook, 2017
Sk. Md. Mizanur Rahman, Hussein T. Mouftah
For successful identification, the Temp ID should be unique for each session of communication. To this end, H should be collision resistant. Theoretically proven collision-resistant hash functions are slow; thus, in practice, hash functions that are expected to be collision-resistant, such as Message Digest algorithm 5 (MD5) [12] and Secure Hash Algorithm 1(SHA-1) [13], are used instead. The probability of finding a collision for MD5 with respect to 128-bit output and that for SHA-1 with respect to 160-bit output have been estimated as, on average, 264 and 280, respectively. As long as these probabilities hold, it is difficult to find the same Temp ID for different nodes in each session of communication.
Securing Future Autonomous Applications Using Cyber-Physical Systems and the Internet of Things
Published in Amit Kumar Tyagi, Niladhuri Sreenath, Handbook of Research of Internet of Things and Cyber-Physical Systems, 2022
S. Sobana, S. Krishna Prabha, T. Seerangurayar, S. Sudha
Secure hash algorithms (SHA) is the widely used cryptographic functions designed to maintain data security in the Internet based autonomous applications. Hash function in SHA performs bitwise operations, compression functions and modular additions. Then it produces a fixed size string similar to that of the original message. SHA algorithms are designed to be one-way functions. SHA-1, SHA-2, and SHA-3, are some of the successful versions of SHA algorithms against the hacker attacks [137]. SHA is widely used mainly in encrypting passwords and detect the tampering of data by attackers. SHA also uses avalanche effect, where the modification of few letters in the message results in a big change in the output [138].
A secure hash function based on feedback iterative structure
Published in Enterprise Information Systems, 2019
Yijun Yang, Fei Chen, Jianyong Chen, Yong Zhang, Kai Leung Yung
On the other hand, serial hash functions should compress all message blocks one by one. The relationship among outputs of every compression functions is hereditary, which is beneficial to message diffusion effect. The most popular hash types currently in use are message digest algorithms (such as MD4, MD5) and secure hash algorithms (such as SHA1, SHA2). It is well known that MD4, MD5, SHA1 and SHA2 (including SHA224, SHA256, SHA384, SHA512) suffer from some common attacks because their similar iterative structure (Wang, Yin, and Yu 2005, Boer and Bosselaers 1994, Dobbertin date unknown, Chabaud and Joux 1998, Liang and Lai 2005, Mendel, Nad, and Schlaffer 2013, Sasaki et al. 2007, Stevens 2013, Wang et al. 2004). SHA3 (Keccak) uses sponge iterative structure which is the latest hash function announced by NIST (Bertoni, Daeman, and Peeters n.d). Although SHA3 can resist the above attacks, its vulnerability has been found by the third party cryptanalysis (Bertoni, Daeman, and Peeters n.d).
A Novel Chaotic Image Encryption Scheme Based on Hash Function and Cyclic Shift
Published in IETE Technical Review, 2019
Xingyuan Wang, Siwei Wang, Na Wei, Yingqian Zhang
SHA-2 is a one-way hash function and no collisions have been found until now. SHA-2 hash standard underlies four secure hash algorithms: SHA-224, SHA-256, SHA-384, and SHA-512. These algorithms are the result of a continuous development of SHA-1. SHA algorithms are used to convert an input message into a condensed fixed length representation called message digest. The security of SHA-256, SHA-384, and SHA-512 with complexity of the best attack as , , and , respectively, have been announced on the ECRYPT2 Yearly Report [21]. In ref. [22], both the theoretic analyses and the numerical simulations showed that the proposed hash encryption algorithm possesses good statistical properties, strong collision resistance, high efficiency, and can overcome the flaws in some other encryption schemes.