User J.D.

31 votes

Reason why “XOR” is a linear operation, but ordinary “addition” isn’t?

answered Dec 28, 2013 at 16:40

22 votes

Why is the permutation in AES (and other ciphers) not random or key-dependent?

answered Apr 12, 2016 at 13:05

20 votes

Accepted

Why does only length prepending improve the security of CBC-MAC

answered Oct 19, 2013 at 10:36

16 votes

Accepted

How exactly is "true randomness" defined in the realms of cryptography?

answered Oct 5, 2013 at 16:48

11 votes

Accepted

Why is the DES s-box non-linear? Why does it make the cracking of the cipher more difficult?

answered Jul 12, 2016 at 11:58

10 votes

Accepted

How to deal with a cipher with addition and XORs combined together?

answered Jul 1, 2016 at 15:58

9 votes

Accepted

Implement AES-CTR on top of AES-ECB

answered Mar 11, 2017 at 23:21

9 votes

Accepted

Discrete logarithm problem is easy in a cyclic group of order a power of two

answered Apr 2, 2016 at 12:16

9 votes

Why do cryptographic hashing and symmetric encryption use different functions?

answered May 6, 2016 at 11:15

9 votes

Accepted

Why have round constants in hashes?

answered Jul 10, 2015 at 13:41

9 votes

Accepted

Non-linearity of a boolean function

answered Oct 18, 2013 at 11:41

8 votes

Accepted

Is this really the correct way to do an IND-CPA test?

answered Oct 1, 2013 at 1:57

7 votes

One-Time Pad Distribution of Keys Between Two Parties

answered Oct 12, 2013 at 1:19

7 votes

Accepted

Why does CBC-MAC need prefix-free inputs to be a good PRF?

answered Nov 1, 2013 at 22:41

7 votes

Accepted

Proof that IND$-CPA implies IND-CPA?

answered Sep 21, 2013 at 14:50

6 votes

Accepted

How do we prove that AES, DES etc. are secure?

answered Oct 7, 2013 at 1:02

6 votes

Why are huge prime numbers important in cryptography?

answered Oct 7, 2013 at 2:37

6 votes

Accepted

What is the intuition behind AES or SPN?

answered Oct 9, 2013 at 14:16

6 votes

Help with breaking AES reduced to 2 rounds

answered Mar 6, 2016 at 14:39

6 votes

Theoretical security of bit rotation for encyption

answered Jan 30, 2016 at 4:11

5 votes

Accepted

LED cryptography algorithm

answered May 30, 2015 at 3:13

5 votes

Accepted

How to prove the security of block ciphers

answered May 4, 2016 at 1:03

5 votes

We can obtain "absolutely perfect CONFIDENTIALITY" using the one-time pad. Is there such a thing as "absolutely perfect INTEGRITY"?

answered Jun 26, 2016 at 13:21

5 votes

Accepted

Chance of finding the right key by exhaustively searching on half of the key space

answered Jul 8, 2016 at 19:39

5 votes

implication of tweak on bruteforcing a block cipher

answered Jan 8, 2014 at 13:09

5 votes

Impact of distinguishing between random text and cipher text?

answered Jan 23, 2014 at 18:07

5 votes

Accepted

How to prove that someone encrypted a specific (large) chunk of data

answered May 25, 2015 at 14:08

5 votes

Accepted

Is the reduction from left-or-right IND-CPA to real-or-random IND-CPA tight?

answered Jun 7, 2015 at 15:02

4 votes

Which symmetric cipher is best for studying?

answered Jun 22, 2015 at 13:43

4 votes

Are pseudorandom permutation really permutation in mathematical sense?

answered May 24, 2015 at 22:40

Stack Exchange Network

67 Answers

Reason why “XOR” is a linear operation, but ordinary “addition” isn’t?

Why is the permutation in AES (and other ciphers) not random or key-dependent?

Why does only length prepending improve the security of CBC-MAC

How exactly is "true randomness" defined in the realms of cryptography?

Why is the DES s-box non-linear? Why does it make the cracking of the cipher more difficult?

How to deal with a cipher with addition and XORs combined together?

Implement AES-CTR on top of AES-ECB

Discrete logarithm problem is easy in a cyclic group of order a power of two

Why do cryptographic hashing and symmetric encryption use different functions?

Why have round constants in hashes?

Non-linearity of a boolean function

Is this really the correct way to do an IND-CPA test?

One-Time Pad Distribution of Keys Between Two Parties

Why does CBC-MAC need prefix-free inputs to be a good PRF?

Proof that IND$-CPA implies IND-CPA?

How do we prove that AES, DES etc. are secure?

Why are huge prime numbers important in cryptography?

What is the intuition behind AES or SPN?

Help with breaking AES reduced to 2 rounds

Theoretical security of bit rotation for encyption

LED cryptography algorithm

How to prove the security of block ciphers

We can obtain "absolutely perfect CONFIDENTIALITY" using the one-time pad. Is there such a thing as "absolutely perfect INTEGRITY"?

Chance of finding the right key by exhaustively searching on half of the key space

implication of tweak on bruteforcing a block cipher

Impact of distinguishing between random text and cipher text?

How to prove that someone encrypted a specific (large) chunk of data

Is the reduction from left-or-right IND-CPA to real-or-random IND-CPA tight?

Which symmetric cipher is best for studying?

Are pseudorandom permutation really permutation in mathematical sense?