Explanation: Out of the given options playfair cipher is the hardest cipher to break using frequency analysis. It is because it does not substitute letters of the word individually but it encrypts them in pairs of two.
Which of the following algorithm uses matrix for encryption and decryption?
3) Which of the following cipher techniques include the involvement of matrix operations in their algorithms of encryption and decryption? Explanation: The hill cipher includes a square matrix as the key, and in Playfair cipher, we create a 5X5 matrix using the given key string.
Which of the following is hardest to break using frequency analysis?
Which of the following is hardest to break using frequency analysis? Explanation: Out of the given options hill cipher is the hardest cipher to break using frequency analysis. Although it is quite vulnerable to other forms of attack.
Which cipher is represented by the following function?
8. Which cipher is represented by the following function? Explanation: The given function represents hill cipher . It is a type of poly alphabetic substitution which is based on linear algebra.
Which of the following is the major drawback of ECB?
The disadvantage of this method is a lack of diffusion . Because ECB encrypts identical plaintext blocks into identical ciphertext blocks, it does not hide data patterns well. ECB is not recommended for use in cryptographic protocols.
What is Monoalphabetic Cipher example?
Monoalphabetic cipher is a substitution cipher in which for a given key, the cipher alphabet for each plain alphabet is fixed throughout the encryption process. For example, if ‘A’ is encrypted as ‘D’, for any number of occurrence in that plaintext, ‘A’ will always get encrypted to ‘D’.
Is Hill cipher block cipher?
The Hill cipher is an example of a block cipher . A block cipher is a cipher in which groups of letters are enciphered together in equal length blocks. The Hill cipher was developed by Lester Hill and introduced in an article published in 1929[1].
What is vigenere Cipher example?
The vigenere cipher is an algorithm of encrypting an alphabetic text that uses a series of interwoven caesar ciphers. It is based on a keyword’s letters. It is an example of a polyalphabetic substitution cipher .
What is a cipher algorithm?
A cipher algorithm is a mathematical formula designed specifically to obscure the value and content of data . Most valuable cipher algorithms use a key as part of the formula. This key is used to encrypt the data, and either that key or a complementary key is needed to decrypt the data back to a useful form.
What is an algorithm in encryption called?
A symmetric key algorithm (also known as a secret key algorithm) , uses the concept of a key and lock to encrypt plaintext and decrypt ciphertext data. The same “key” is used to both encrypt and decrypt the file. ... A stream cipher is where plaintext digits are combined with a pseudo-random cipher digit stream.
Which block is cipher?
A block cipher is an encryption method that applies a deterministic algorithm along with a symmetric key to encrypt a block of text, rather than encrypting one bit at a time as in stream ciphers. For example, a common block cipher, AES , encrypts 128 bit blocks with a key of predetermined length: 128, 192, or 256 bits.
Is vigenere cipher Monoalphabetic?
Vigenère cipher, type of substitution cipher used for data encryption in which the original plaintext structure is somewhat concealed in the ciphertext by using several different monoalphabetic substitution ciphers rather than just one; the code key specifies which particular substitution is to be employed for ...
Which technique is book cipher?
A book cipher, or Ottendorf cipher, is a cipher in which the key is some aspect of a book or other piece of text. Books, being common and widely available in modern times, are more convenient for this use than objects made specifically for cryptographic purposes.
Is Initialization a vector secret?
4 Answers. An initialization vector needs not be secret (it is not a key) but it needs not be public either (sender and receiver must know it, but it is not necessary that the Queen of England also knows it).
Why is ECB not secure?
The main reason not to use ECB mode encryption is that it’s not semantically secure — that is, merely observing ECB-encrypted ciphertext can leak information about the plaintext (even beyond its length, which all encryption schemes accepting arbitrarily long plaintexts will leak to some extent).
Is AES CTR secure?
CTR: An IV-based encryption scheme, the mode achieves indistinguishability from random bits assuming a nonce IV. As a secure nonce-based scheme, the mode can also be used as a probabilistic encryption scheme, with a random IV. Complete failure of privacy if a nonce gets reused on encryption or decryption.
