The Null Cipher, also known as the Null Encryption or Null Message, is a simplistic cryptographic technique where specific letters or symbols are deliberately left blank or null in a message. Instead of using complex algorithms or substitutions, the Null Cipher relies on the absence of characters to convey hidden information.
To encrypt a message using the Null Cipher, certain spaces or positions within the text are intentionally left empty, while the rest of the message may contain ordinary text or plaintext. This arrangement of blanks or nulls forms a hidden pattern that carries the concealed message.
Decryption of the Null Cipher involves recognizing the empty spaces or null positions in the message and extracting the concealed information accordingly. The recipient must be aware of the specific rules or pattern used by the sender to successfully uncover the hidden message.
The Null Cipher's simplicity makes it relatively weak as an encryption method, and it can be vulnerable to frequency analysis or other simple cryptographic attacks. Consequently, the Null Cipher is generally considered more of an amusing historical curiosity rather than a secure encryption technique, and it is not commonly used for serious cryptographic purposes.