Linear cryptanalysis is a known plaintext attack and uses a linear approximation to describe the behavior of the block cipher. Given sufficient pairs of plaintext and corresponding ciphertext, bits of information about the key can be obtained and increased amounts of data will usually give a higher ...

learn more… | top users | synonyms

0
votes
1answer
18 views

linear cryptanalysis: how are the subkey bits removed from the linear approximation?

I'm currently reading the tutorial on linear/differential crypta here: https://www.engr.mun.ca/~howard/PAPERS/ldc_tutorial.pdf End of page 14/Beginning of page 15: all the bits from the subkeys are ...
0
votes
1answer
140 views

How does non-linearity (S-box) add security to AES?

I'm trying to understand how AES guarentees security. One of the named points on the web is that AES uses a non-linear step (the SubBytes step). But how exactly does the Rijndael key schedule add ...
3
votes
0answers
33 views

Breaking linear blockcipher - expanding recursive formula

I am trying to break a block cipher that can be defined as follows: We have 12 rounds and at each round we perform the following operation. We split 64 bit data into 2 parts each 32-bits, $\ x_r$ ...
2
votes
0answers
72 views

Matsui's Linear attack on DES P box

I'm trying to understand Matsui's linear attack on DES and I have something I don't understand in his paper. In his paper he say that: $NS_{5}(16,15)=12$ (which is OK) and from that he say that: $X[...
1
vote
0answers
70 views

Differential bound of the S-Box in GOST R34.11-2012

In Russian GOST R34.11-2012 LPS-transformation is used. LPS gets all of its non-linearity from the 8-bit S-box S, which apparently has been designed to offer resistance against classical methods of ...
1
vote
0answers
35 views

How to apply linear cryptanalysis to PRESENT?

Can someone help me implement linear cryptanalysis of the PRESENT block cipher? How should I start with 64 bits of plaintext and 80 bits of key?
-1
votes
0answers
19 views

A5/2 Ciphertext Only Attack

I've studied that A5/2 could be attacked with cipher-text only, using the Error Correction Code, in order to retrieve the session key. Here's an article I tried to read about it (section 4). (however ...