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Network Reliability and Security
Published in Partha Pratim Sahu, Advances in Optical Networks and Components, 2020
Any encryption system should secure the plaintext against a chosen-plaintext attack. If it is possible, then it must secure against a known-plaintext attack. Failing this, it should secure also at least to immune to a ciphertext-only attack. The ciphers become either secret or public [24]. In a conventional (secret) cipher, the same key is used to encrypt and decrypt a message. Such a key must obviously remain secret. For a public key cipher (which is also known as an asymmetric or a two-key cryptosystem), different keys are used to encrypt and decrypt a message [25]. These keys have a pair of transformations, each of which is the inverse of the other and neither of which is derivable from the other. The encryption key is made publicly known, whereas the corresponding decryption key remains secret.
Wireless Sensor Networks (WSNs)
Published in Chanchal Dey, Sunit Kumar Sen, Industrial Automation Technologies, 2020
Cryptography ensures a secure communication between a transmitter and a receiver. In this, an ordinary or plain text is converted into cipher text (this process is called encryption) at the transmitter and decryption at the receiver. Data encryption requires an algorithm and a key. While the algorithm may not be secret, total secrecy is maintained about the key used for encryption. The number of bits comprising a key is considerable and it is just impossible to get the composition of the key. Two types of cryptography are employed: symmetric and asymmetric. In a symmetric cryptosystem, the same key is used for encryption and decryption, while separate keys are used in asymmetric cryptosystem. Cryptography ensures data integrity, confidentiality, and device and message authentication. The security strength of any cryptosystem depends on the key used and not on the algorithm.
Key Management
Published in Khaleel Ahmad, M. N. Doja, Nur Izura Udzir, Manu Pratap Singh, Emerging Security Algorithms and Techniques, 2019
Cryptographic system or cryptosystem is a suite of cryptographic algorithms, keys, and key management protocols for securing the message traveling over the unsecure networks between the entities. The cryptographic algorithms ensure the secrecy, privacy, and authenticity of the communicated message between the entities. It involves ciphers, keys, plaintext, and ciphertext for the encryption of the message. There are two types of cryptography algorithms in the cryptographic system: symmetric (secret key) and asymmetric (public key) cryptography algorithms. Symmetric key cryptography uses the same key commonly known as the secret key for the encryption and decryption of the message, whereas asymmetric key cryptography algorithm uses public and private keys for the encryption and decryption of the message. Hence, there are three types of keys involved in the cryptographic algorithm: secret key, private key, and public key for ensuring the secrecy of the message over the unsecured networks. For ensuring the secrecy of the message, cryptographic keys must be managed efficiently and is done by key management system.
Design and verification of improved CMERE against power analysis attacks
Published in Cyber-Physical Systems, 2020
Hridoy Jyoti Mahanta, Abhilash Chakraborty, Ajoy Kumar Khan
Fundamentally cryptosystems are of two types: Symmetric cryptosystem and Asymmetric cryptosystem. Symmetric cryptosystem uses the same key for encrypttion as well as decryption whereas asymmetric cryptosystem uses two different keys for both these operations. There are numerous algorithms and methods developed to secure data exchange which follow the basic concept of these two cyptosystems; among them, RSA is a type of secure asymmetric cryptosystem. It is very popular as it offers both confidentiality and authentication. The mechanism of RSA is comprehensively explained in algorithm 1. Here, ‘m’ is the message, ‘n’ is the modulus, ‘p’ and ‘q’ are the two large primes numbers used for generation of keys and ‘z’ is Euler’s Totient function [2].
A block encryption algorithm based on exponentiation transform
Published in Cogent Engineering, 2020
Nursulu Kapalova, Ardabek Khompysh, Müslüm Arici, Kunbolat Algazy
Cryptographic methods of protection are certainly the most reliable protection techniques, since they secure the information itself, but not access to it. Modern cryptography includes four major sections: symmetric cryptosystems; public-key cryptosystems; digital signature; and key management (Nyssanbayeva et al., 2016). Symmetric cryptosystems use the same key for both encryption and decryption. The whole variety of existing cryptographic methods in symmetric cryptosystems can be reduced to the following four classes of transformations: substitution, where the characters of the encrypted text are replaced by characters of the same or another alphabet under a predetermined rule;permutation, where characters of the encrypted text are rearranged according to a certain rule within a given block of the transmitted text;analytical transformation, where the encrypted text is converted according to a certain analytical rule, for example, additive stream cipher involves modular addition of the source text by a pseudorandom sequence generated on the basis of the key;combined transformation represents a sequence of basic transformation techniques applied to a block (part) of the text under encryption.
Leveraging the power of quantum computing for breaking RSA encryption
Published in Cyber-Physical Systems, 2021
Moolchand Sharma, Vikas Choudhary, R. S. Bhatia, Sahil Malik, Anshuman Raina, Harshit Khandelwal
Symmetric key cryptosystem uses the same key for encryption as well as decryption, and for this reason, these systems generally require a secure and a different channel to communicate a passphrase between the sender and the receiver. Thus, this channel of communication must be reliable and trusted. However, in the asymmetric cryptosystems, this is not the case. The communication in public-key cryptosystem can be through public, untrusted mediums like the internet. But one must be varying that the key being transmitted belongs to the person they want to communicate with. Also, due to a reason, some form of interaction might still be required between the key holders (the type of communication can be direct or indirect) as it is only a single time process [7].