Comment on the significance and benefit of using the sequence of constants. Perh
ID: 3639573 • Letter: C
Question
Comment on the significance and benefit of using the sequence of constants.
Perhaps the simplest "serious" symmetric block encryption algorithm is the Tiny Encryption Algorithm (TEA). TEA operates on 64-hit blocks of plaintext using a 128-bit key. The plaintext is divided into two 32-bit blocks (L0, R0), and the key is divided into four 32-hit blocks (K0, K1, K2, K3). Encryption involves repeated application of a pair of rounds defined as follows for rounds i and i + 1: Li = Ri - 1 where F is defined as and where the logical shift of x by y hits is denoted by x y: and delta i is a sequence of predetermined constants.Explanation / Answer
If the particular sequence of constants was changed from encryption algorithm to encryption algorithm, then only the person who encrypted the ciphertext would be able to read it. Essentially, the sequence of constants would act as another key the anyone who wants to decrypt the ciphertext would need to know.