Cipher Encryption is the process of encoding plaintext into an unreadable ciphertext. The encryption algorithm specifies how a message is to be encoded. The authorized should be able to decode the ciphertext using a decryption algorithm. ROT 13 The ROT-13 (Rotate by 13) cipher is a rudimentary cipher that shifts each letter 13 spaces. For example, the letter A becomes the letter N. The letter B becomes the letter O. C becomes P, so on and so on. Decoding the cipher simply rotates the letters back 13. readable: Change this readable text into unreadable ciphertext by clicking the Encrypt button. ROT-13 (Rotate by 13) cipher is a cipher that shifts each letter 13 spaces. The letter A becomes the letter N. The letter B becomes the letter O. C becomes P, so on and so on. Decoding the cipher simply rotates the letters back 13. Encrypt > < Decrypt cipher: