7
votes
3answers
2k views

How to attack a classical cipher using known partial plaintext?

I have a ciphertext generated by a classical cipher. I do not know what was cipher used to generate it. I do however have the beginning of the plaintext. What are the cryptanalysis approaches for ...
15
votes
2answers
2k views

What are the main weaknesses, if any, of a Playfair cipher?

What are the main weaknesses, if any, of a Playfair cipher? I know that they depend on none of the letters missing, but that is an easy fix if a letter gets dropped. Besides that, are there any other ...