Lines to be cracked

Usage examples of ciphertext.

Another normal alphabet, which merely repeats the initial letters of the horizontal ciphertext alphabets, runs down the left side.

English, the cryptanalyst will count the number of letters in the ciphertext.

A semagram is a steganogram in which the ciphertext substitutes consist of anything but letters or numbers.

An algorithm that runs through a ciphertext, trying all patterns in the order of likelihood.

Thus the ciphertext 828115125 can be unambiguously divided as828115125 and deciphered to Espana.

To decrypt, generate the same keystream and subtract modulo 26 from the ciphertext to recover the plaintext.

Subtract the keystream numbers from the ciphertext numbers, modulo 26.

Just minutes ago she had completed her usual log-on to the proxy server and noticed that a ciphertext E-mail had arrived.

The second letter in Enoch's ciphertext is S, which is the nineteenth letter in the alphabet, and subtracting four from that gives him O.

He generates a 23 and then a 47 which, modulo 26, is 21, and subtracting the 23 and the 21 from the next two ciphertext letters K and J (again, modulo 26) gives him N and O as expected.

Normally, one begins by figuring out, based on certain patterns in the ciphertext, whether it is, for example, a substitution or a transposition system, and then further classifying it into, say, an aperiodic transposition cipher in which keying units of constant length encipher plaintext groups of variable length, or vice versa.