Answer: The process of encrypting blocks of plaintext by putting them through a series of substitution and permutation operations using a specific encryption algorithm is called a block cipher.
Block ciphers operate on fixed-length groups of bits, or blocks, and transform them into the same-sized blocks of ciphertext. The block cipher takes a block of plaintext as input, performs a series of substitution and permutation operations according to a secret key, and outputs a block of ciphertext. The same key is used to encrypt and decrypt the data.
Block ciphers are commonly used in symmetric-key encryption algorithms such as AES (Advanced Encryption Standard) and DES (Data Encryption Standard).
Step-by-step explanation: