A cryptogram is generated by combining plaintext in a cryptographic process with a key, which is a combination of bits, in a logical operation. The result is the ciphertext. The ciphertext consists of a cryptic sequence of letters and digits that does not allow any conclusions to be drawn about the plaintext. The ciphertext only becomes plaintext again when it is decrypted, during which the encrypted text is again linked to the ciphertext key.
The ciphertext alphabet on which the ciphertext is based is generated from the characters to which the plaintext is mapped. A ciphertext alphabet can consist of letters, digits and characters.