Tagged Questions
9
votes
7answers
440 views
C: replace AES FIPS-197 SubBytes table by constant-time code
In FIPS-197 (the Advanced Encryption Standard, known as AES), it is made heavy use of SubBytes, which could be implemented as
unsigned char SubBytes(unsigned char x) {
static const unsigned char ...
8
votes
2answers
497 views
Decryption by pattern analysis
You are given an encrypted string, encrypted using a very simple substitution cipher.
Problem
You do not know what the cipher is but you do know the ciphertext is English and that the most frequent ...
11
votes
5answers
889 views
Write Buggy Code
Now is the time to show off your abilities to write bad code. I am trying out a new sort of programming puzzle, most similar, I think, to the underhanded C contest. The main difference is that this is ...
27
votes
4answers
877 views
Underhanded Password Hashing
In the spirit of the Underhanded C Contest, I'm starting an Underhanded Code Contest. The objective of this contest is to straightforwardly implement some code, while subtly hiding a nefarious bug ...
7
votes
2answers
472 views
Break the broken cipher
I have designed a simple random generator that cycles two numbers in a chaotic way using a multiply and modulus method. It works great for that.
If I were to use it as a cipher generator it would ...
