Are there any strong manual ciphers?
91313
Is there any strong enough pen-and-paper or mind cipher?
82535
Is a small size block cipher usable?
79203
Brute-force attacking One Time Pads feasible?
40774
Is one time pad cipher reuse and random key secure?
143728
Is there a way of maintaining malleability in a homomorphic encryption system while making it infeasible to perform chosen ciphertext attacks?
98404
Is there a simple hash function that one can compute without a computer?
81780
Encrypting and/or decrypting ciphertext with the provided Initialization Vector (IV)
79642
Is there a secure cryptosystem that can be performed mentally?
64779
A simple block cipher based on the SHA-256 hash function
12035
XOR cipher with fixed key and known relation among plaintexts
83164
How to break a Quagmire 3 cipher?
67716
Any practical uses of machine learning for cryptography?
36116
What is the best way to put a backdoor in an encryption system?
90079
Theoretical pi-based stream cipher
51626
Is a known plaintext, ciphertext, and public-key a viable attack on RSA?
138951
Affine cipher: calculate the key from a known plaintext/ciphertext pair
52243
Which hash algorithm is most secure for passwords?