Steganography is a technology for hiding information. Its principle is to embed a piece of plain text information into another piece of seemingly meaningless information, so that external observers cannot detect the existence of the information.

Steganography is a skill and science about information hiding. The so-called information hiding refers to not letting anyone except the intended recipient know the transmission event or the content of the information.

Invisible ink, digital watermarks and letter frequencies are all principles of steganography.

The Baconian cipher is a steganography technique invented by Francis Bacon. The encryption principle first converts each letter in the plaintext into a set of five English letters. The conversion table is as follows: For example, the plain text "ILOVEYOU" is converted into ABAAAABABBABBBABABABAABAABBAAAABBBABABAA.

The third party is neither aware of the existence of the secret information nor aware that the secret information exists. Therefore, keys, digital signatures and private information can be transmitted securely in an open environment (such as the Internet, or an intranet). Mainly introduces the basic principles and various applications of steganography.