Detailed AES
Before we explore how round cipher works, let me discuss one of the most used cipher in today’s world the AES. AES processes information in 128 bits per block and allows 128-bit, 192-bi,t, or 256-bit keys. Here’s a simplified overview of its encryption process:
Initial Round
- AddRoundKey: Before the rotation, the plaintext block is combined with one of the round keys through an XOR operation.
Main Rounds (9, 11, or 13 rounds depending on the key size)
- SubBytes: In three cases each byte of state array is replaced with the value of that S-box.
- ShiftRows: Shift the rows of the state array cyclically.
- MixColumns: The given state array is transposed and the columns of this array are combined, for example, by addition with different real coefficients.
- AddRoundKey: Elements from the state array are then processed through the XOR gate with an incoming round key.
Final Round
- SubBytes
- ShiftRows
- AddRoundKey
Consequently, each of these steps introduces increased levels of difficulty, which makes the AES one of the most secure algorithms of encryption in existence today.
What is Round Cipher?
Round ciphers are also known as block ciphers, and they are a classification of encryption algorithms that work systematically, converting the plaintext into ciphertext. These algorithms work on a limited number of bits at a time and subject them to a set of mathematical processes called rounds which are used to bring about the act of encryption. It continually becomes progressively more rigid to attack the data without the correct key, each round is added to the security of the data. These are the operation sequences of a round that include substitution, permutation, key mixing, and input data.
Contact Us