What is key dependent s box?
Abstract. Key-dependent S-boxes have recently gained prominence as a component in block cipher design. In fact, at an abstract level, we ob- serve that the notion of S-boxes that change from encryption to encryption can be quite useful to an attacker.
What do you mean by differential cryptanalysis?
Differential cryptanalysis seeks to find the difference between related plaintexts that are encrypted. It is usually launched as an adaptive chosen plaintext attack; the attacker chooses the plaintext to be encrypted (but does not know the key) and then encrypts related plaintexts. …
How many inputs and outputs are there in each S box?
Each S-box has a 6-bit input and a 4-bit output, and there are eight different S-boxes. (The total memory requirement for the eight DES S-boxes is 256 bytes.) The 48 bits are divided into eight 6-bit sub-blocks.
How many S boxes are used in AES?
In order to transform 128-bit input data, a total of 16 ROM structures of S-Box are utilised which enormously increase the hardware complexity in the AES algorithm.
What is differential and linear cryptanalysis?
The two main classes of statistical cryptanalysis are the linear and differential attacks. The idea of differential-linear cryptanalysis is to apply first a truncated differential attack and then a linear attack on different parts of the cipher and then combine them to a single distinguisher over the cipher.
What are three basic variations of cryptanalysis?
There are three generic types of cryptanalysis, characterized by what the cryptanalyst knows: (1) ciphertext only, (2) known ciphertext/plaintext pairs, and (3) chosen plaintext or chosen ciphertext.
What is the input and output bits for S-boxes?
Given a 6-bit input, the 4-bit output is found by selecting the row using the outer two bits (the first and last bits), and the column using the inner four bits. For example, an input “011011” has outer bits “01” and inner bits “1101”; the corresponding output would be “1001”.
What are S boxes in AES?
The substitution bytes (S-Box) in AES algorithm plays an important role as it provides confusion in the cipher text [10, 11]. The basic function of S-Box is to transforms the 8 bits input data into 8 bits secret data using a precomputed look-up-table (LUT).
How is S-Box created in AES?
S-Box is constructed by composing two transformation – multiplicative inverse in Galois Field GF(2 8 ) followed by an affine transformation. The S-Box is the most time and power consuming component of AES Algorithm. The time consumption for AES S-Box is decreased by the proposed affine transformation.
What are the methods of cryptanalysis?
Cryptanalysis techniques for stream ciphers are:
- Exhaustive Key Search Attack.
- Side Channel Analysis Attack.
- Time Memory Trade off Attacks.
- Distinguishing Attacks.
- Algebraic Attack.
- Correlation attacks.
- Guess and Determine attacks.
- Linear Masking attacks.