Question

1. a _________ is an encryption/decryption scheme in which a block of plaintext is treated as a whole and used to produce a ciphertext block of equal length.

Answer 1

A block cipher is an encryption/decryption scheme in which a block of plaintext is treated as a whole and used to produce a ciphertext block of equal length.

How do block ciphers work?

Block ciphers, which use a deterministic algorithm and a symmetric key, are used to encrypt blocks of data. The majority of encryption algorithms encrypt bits one at a time, much like how stream ciphers function (stream ciphers). On the other hand, a block cipher uses keys that are 128, 192, or 256 bits long to encrypt blocks of 128 bits.

Why is des called block cipher?

Since DES is a block cipher, it encrypts data in blocks of 64 bits each. As a result, DES receives 64 bits of plain text as input and outputs 64 bits of ciphertext. With a few minor variations, the same algorithm and key are utilized for encryption and decryption.

Learn more about block ciphers: https://brainly.com/question/13267401

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