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Cryptosystem for Meshed 3D through Cellular Automata
Published in Ali Ahmadian, Soheil Salahshour, Soft Computing Approach for Mathematical Modeling of Engineering Problems, 2021
R. Sulaiman, M.A. Al-Jabbar, A. Ahmadian, A.M.A. Abdalla
Keyspace in encryption schemes has to be very large to impede brute-force attacks. For that reason, the secret key used by the FcCA cryptosystem is comprised of two flexible sub-keys: HCA and a numeric set containing the Ps series and iDL coordinates. Unlike most existing encryption schemes with conventional CA, this key structure provides more flexibility to change the sizes of those sub-keys freely and easily, based on the required level of protection. The dimensions of CA and the length of the generated keys partially depend on the size of the original image or object. Nonetheless, the lengths of sub-keys depend on numerous parameters; specifically, the dimensions of HCA, the (G + Ps)-bit length of each cell in HCA, the number of elements within the Ps series, and the coordinates of iDL points.
Introduction
Published in Jonathan Katz, Yehuda Lindell, Introduction to Modern Cryptography, 2020
The set of all possible keys output by the key-generation algorithm is called the key space and is denoted by K. Almost always, Gen simply chooses a key uniformly from the key space; in fact, one can assume without loss of generality that this is the case (see Exercise 2.1).
Overview of Cryptography
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 size of the key space is the number of encryption/decryptionkey pairs that are available in the cipher system. A key is typically a compact way to specify the encryption transformation (from the set of all encryption transformations) to be used. For example, a transposition cipher of block length t has t! encryption functions from which to select. Each can be simply described by a permutation which is called the key.
Protection of COVID-19 images using multiple elliptic curve cryptography
Published in The Imaging Science Journal, 2023
Diana Laishram, N. Tuturaja Singh, Khumanthem Manglem Singh
The collection of all potential keys is known as the key space, which is used in the encryption of a cryptographic algorithm. If denotes a key and denotes the key space, then it can be represented as . If a key is string of n bits, then its key space is the collection of all binary strings of length n bits, i.e. key space is of size . The key length or space for a strong encryption technique needs to be sufficiently large to fend off assaults and an effective key length should be above for all possible keys [49]. The total key space for the proposed technique is . This value is large enough in comparison with other schemes as in Table 6.
A public and private key image encryption by modified approach of Vigener cipher and the chaotic maps
Published in The Imaging Science Journal, 2023
Umar Hussain Mir, Parveiz Nazir Lone, Deep Singh, D. C. Mishra
An image encryption algorithm is said to have robustness against brute-force attacks if it has a large keyspace. A good brute-force resistant algorithm suggests the keyspace size equal to at least . The keyspace is just a total number of permutations of input key parameters. The proposed algorithm has four input keys of 8 tuples in the diffusion phase and width values of rectangles as keys in the confusion phase. So for an 8-bit image, the keyspace in the diffusion phase is and in the confusion phase is approximately [6]. Thus the total keyspace of the proposed system is which is relatively larger than the theoretical size. Thus the large keyspace of the proposed algorithm suggests that it is highly resistant to brute-force attacks.
Design of a secure communication system between base transmitter station and mobile equipment based on finite-time chaos synchronisation
Published in International Journal of Systems Science, 2020
Somayeh Hashemi, Mohammad Ali Pourmina, Saleh Mobayen, Mahdi R. Alagheband
The key-space size for a cryptosystem is based on the total number of different keys utilised in the encryption. A good cryptosystem should possess a key space which is large enough to resist all kinds of brute-force attacks. These types of attacks are actually based on the exhaustive key search. In the proposed algorithm, if eavesdroppers want to extract the plain-text from the encrypted signal, they will require the system parameters , and , the initial conditions , , of the chaotic system (Equation (1)) and the synchronisation parameters ,,,,,, of Equations (43) and (44) as secret keys. All of these secret keys are considered as type double, which has 15-digit accuracy. Therefore, the key space becomes as huge as . Thus, the proposed algorithm possesses a large key-space which is capable of resisting to all possible kinds of statistical attacks.