Tagged Questions
3
votes
6answers
336 views
Where can I begin to study the math behind modern cryptography?
I've been studying (more like breathing and eating) crypto for almost a year now, implementing algorithms, reading books, studying code, etc. The deeper I go in, the more I realize there is; I feel ...
1
vote
2answers
158 views
How hard is to find the operators of an addition knowing the sum of them?
I want to learn whether or no there is a cryptographic primitive,scheme assumption that is based on the following hard problem if it is hard . By hard we mean that we have a polynomial adversary: The ...
6
votes
2answers
718 views
Why do block ciphers need a non-linear component (like an S-box)?
Why is there a requirement of "Non-Linear functions" as a component of many popular block ciphers (e.g. the S-box in DES or 3DES)?
How does it make the cipher more secure?
The only intuition I have ...
3
votes
1answer
217 views
Is XOR in a CBC-like mode secure?
Assuming that $K_{n}$, $P_{n}$, and $C_{n}$ are individual bytes of the key, plaintext, and ciphertext respectively.
The first byte of ciphertext is computed like this:
$C_{1} = K_{1} \oplus P_{1}$
...
8
votes
3answers
452 views
What is the best way to put a backdoor in an encryption system?
How can you put a backdoor into an encryption algorithm? Are there any techniques that can be used to reduce the time it takes to break a key?
I am looking for practical examples encryption schemes ...
