Is there a way to find $a$ and $b$ keywords in an affine cipher when only ciphertext but no plaintext is known?
138951
Affine cipher: calculate the key from a known plaintext/ciphertext pair
82535
Is a small size block cipher usable?
114300
random access stream cipher
39336
RSA find $q$ given only $e$ and $p$
10729
DES — Can I recover the key when I have both ciphertext and the plaintext?
154948
Decisional Diffie-Hellman: compute Legendre symbol of $g^{ab}$ from $g^a$ and $g^b$?
135593
Decrypting Ciphertext with partial Key Fragment using LFSR and Berlekamp-Massey
3765
Is it possible to obtain AES-128 key from a known ciphertext-plaintext pair?
49053
Knowing the key, how do I decrypt the affine cipher?
109568
For a given plaintext-ciphertext pair, how many valid AES keys are there?
103287
AES-128. Do there exist two different keys for a pair (text, encrypted text)?
91927
How to publish a cipher (concept)?
128850
Proving an encrypted message contains (but does not 100% consist of) a plain-text message?
40477
Is a book cipher provably secure?
100640
K out of N encryption
88031
Possible ways to crack simple hand ciphers?
34578
Kerckhoffs’ principles – Why should I make my cipher public?