1. Breaking the affine cipher using a known plaintext attack You've intercepted the ciphertext 'DEJXDIJYZ'. By bribing somebody you were able to find out that the first and second letters of the corresponding plaintext are 'sn'.

Your answer will consist of values for a, b, a^-1, and -b, all expressed as values between 0 and 25 inclusive, and the plaintext word in letters.

1. Using the crib, find the encryption key, that is, determine a and b so that ax+b=y (mod 26) encrypts 'sn' as 'DE', that is, when x=18 (the letter 's'), y=3 (D) and when x=13 (the letter 'n'), y=4 (E).
2. Using the decryption formula a^-1(y+(-b))=x (mod 26), determine the corresponding decryption key for the encryption key you found in (a).
3. Apply that decryption key to find the original plaintext for 'DEJXDIJYZ'.