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Block Ciphers
Published in Alfred J. Menezes, Paul C. van Oorschot, Scott A. Vanstone, Handbook of Applied Cryptography, 2018
Alfred J. Menezes, Paul C. van Oorschot, Scott A. Vanstone
The cipher named IDEA (International Data Encryption Algorithm) encrypts 64-bit plaintext to 64-bit ciphertext blocks, using a 128-bit input key K. Based in part on a novel generalization of the Feistel structure, it consists of 8 computationally identical rounds followed by an output transformation (see Figure 7.11). Round r uses six 16-bit subkeys Ki(r), 1 ≤ i ≤ 6, to transform a 64-bit input X into an output of four 16-bit blocks, which are input to the next round. The round 8 output enters the output transformation, employing four additional subkeys Ki(9), 1 ≤ i ≤ 4 to produce the final ciphertext Y = (Y1, Y2, Y3, Y4). All subkeys are derived from K.
Symmetric Algorithms I
Published in Khaleel Ahmad, M. N. Doja, Nur Izura Udzir, Manu Pratap Singh, Emerging Security Algorithms and Techniques, 2019
Faheem Syeed Masoodi, Mohammad Ubaidullah Bokhari
IDEA operates on blocks of size 64 bit, and each such block is partitioned into four 16 bit sub-blocks. The encryption operation comprises a total of nine rounds on plaintext blocks, and during round one, all four of these sub-blocks are operated upon by some arithmetic and logical operations. The output of each round is fed as input to the next round, and the same sequence of operations is performed up to round eight. Round nine, also called as the OUTPUT TRANSFORMATION phase, is the final round, and only arithmetic operations are performed in this round. The output of round nine is the resultant ciphertext of the corresponding plaintext.
A novel Sine–Tangent–Sine chaotic map and dynamic S-box-based video encryption scheme
Published in The Imaging Science Journal, 2023
Many video encryption algorithms have been proposed using various technologies such as chaos theory [6–9], traditional encryption algorithms [10,11], selective encryption using Discrete Cosine Transform (DCT) [12,13] and wavelet transform [1,14]. The video data has a large volume, high redundancy and correlation among pixels. Therefore, the traditional encryption algorithms such as Data Encryption Standard (DES), International Data Encryption Algorithm (IDEA), Rivest-Shamir-Adleman (RSA) and Blowfish are not appropriate, as these algorithms do not meet real-time requirements [15] and hence suffer from security issues. Chaos theory has gained popularity among researchers due to its special properties such as unpredictability, randomness, nonlinearity, dense orbits and initial state dependence [16]. Chaotic maps can be classified into two types: high-dimensional and low-dimensional chaotic maps. Low-dimensional chaotic maps have one control parameter, small key space and are easy to implement. Logistic map [17], Chebyshev map [18], Tent map [19], Sine map [20] are examples of low-dimensional chaotic maps. On the other hand, high-dimensional chaotic maps have more than one control parameter and exhibit more complex chaotic behaviour than low-dimensional chaotic maps. Two-dimensional Lorenz system [21], Arnold's cat map [22] and Baker's map [23] are some examples of high-dimensional chaotic maps.
Data Hiding in Iris Image for Privacy Protection
Published in IETE Technical Review, 2018
Sheng Li, Xin Chen, Zichi Wang, Zhenxing Qian, Xinpeng Zhang
Figure 1 shows the iris authentication system considered in this paper. In enrolment phase, the personal privacy data M is firstly encrypted into cipher text M′ using existing encryption algorithms, e.g. data encryption standard (DES), international data encryption algorithm (IDEA) with an embedding key K. Then M′ is embedded into a registered iris image C using a proposed embedding algorithm to obtain the iris image S with secret data. Finally, S is stored in the iris database for authentication. In this phase, only one iris image database is needed, instead of additional storage space.
A Comprehensive Literature of Genetics Cryptographic Algorithms for Data Security in Cloud Computing
Published in Cybernetics and Systems, 2023
Ozgu Can, Fursan Thabit, Asia Othman Aljahdali, Sharaf Al-Homdy, Hoda A. Alkhzaimi
Symmetric cryptographic techniques, asymmetric cryptographic techniques, and hash functions are the three most popular forms of cryptographic techniques. Single-key encryption is used to encrypt or decode data in symmetric techniques. Some examples of symmetric encryption DES: The Data Encryption Standard A.E.S.: Advanced Encryption Standard, CAST: Carlisle Adams and Stafford Tavares method, IDEA: International Data Encryption Algorithm Blowfish, Two fish, and SAFER: Secure and Fast Encryption Routine.