Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [differential-analysis]

Differential cryptanalysis is a form of cryptanalysis which studies cryptographic algorithms by observing how differences in input affect differences in output.

In practice, this is usually a chosen-plaintext attack with a quite large number of plaintexts (but for "broken" algorithms still smaller than the key space).

The terminology is presented by Biham and Shamir and within IBM, the attack was formerly known as the "T-attack" or ”tickle attack.

141 questions
1
vote
0 answers

Are the weaknesses of my functions attackable?

I got specific problem with my functions in $128$-bit block cipher. One round of encryption is like that: $input$ $\rightarrow$ $F(k_{i},input)$ $\rightarrow$ reverse block $\rightarrow$ $F(k_{i+1},reversed \ block)^{-1}$ $\rightarrow$…
Tom
  • 1,221
  • 6
  • 16
1
vote
1 answer

Comparing Difference Distribution Tables

I have been studying the Diff. Cryptanalysis and finding it hard to do a problem. The problem is I have calculated the tables programmatically and found that the second table has a max value of 6 where as the first has a max value of 4.What can i…
algo1
  • 53
  • 4
0
votes
0 answers

I cannot get the meaning of "check s-box"

In second lecture of cryptography, we had a lecture "Block cyphers" and teacher gave me permuted array of numbers 1...10 and letters "a"..."f" and asked me to find XOR profile. But I do not have any idea what I need to do and do not get what XOR…
Moody Lover
  • 1
0
votes
0 answers

Differential attack on repeating pairs of zeros in blocks

Let's consider $5$ types of vulnerabilities in one round of encryption in 128-bit cipher. We got 00 at the beginning of the block (the first two bits are two zeros). We got 00 in the middle of the block. We got 00 at the end of the block. We got 00…
Tom
  • 1,221
  • 6
  • 16
0
votes
0 answers

Trying to attack specific encryption scheme

Let's consider 128-bit cipher. Now let's consider example keys $k_1$ to $k_{128}$: $k_1$: 10 $k_2$: 1100 $k_3$: 11110000 ... In general every key $k_n$ can be some binary number which is consist of $n$ zeros and $n$ ones. This keys are mapping some…
Tom
  • 1,221
  • 6
  • 16
0
votes
1 answer

Are the weaknesses of my s-boxes attackable?

I got specific problem with my s-boxes in $128$-bit block cipher. One round of encryption is like that: input - sbox - reverse block - $sbox^{-1}$ - output Every s-box got specific $128$-bit key. $sbox^{-1}$ means that we are looking for such input…
Tom
  • 1,221
  • 6
  • 16
0
votes
1 answer

Improving differential cryptanalysis of a vulnerable cipher

How to avoid differential cryptanalysis attacks when you are inventing new cipher? Let's say you have a $16$-round $128$-bit cipher vulnerable on differential cryptanalysis attacks. Now let's say you will add between every round: bitwise NOT…
Tom
  • 1,221
  • 6
  • 16