# Key derivation using known parameters of playfair [duplicate]

Is it possible to derive the key, for a playfair cipher, if both the message and cipher text are known?

• Of course, you can. Wikipedia sentence Like most classical ciphers, the Playfair cipher can be easily cracked if there is enough text. Obtaining the key is relatively straightforward if both plaintext and ciphertext are known. Mar 28 at 8:16
• I might call this dupe of this. How to attack a classical cipher using known partial plaintext?. It turns out the OP was asking about PlayFair cipher. I simply foud out this by searching playfair known plaintext on our site. Mar 28 at 10:31