As technology continues to evolve, so do the codes that power our devices and systems. While most codes are readily accessible and open to the public, there are certain codes that are meant to be kept secret. These codes are often used for security and military purposes.

The Kryptos Code: The Kryptos Code is a sculpture located at the CIA headquarters in Virginia. The sculpture contains four encrypted messages, three of which have been solved. The fourth message, however, remains unsolved and is considered to be one of the most difficult code.

The Navajo Code: During World War II, the Navajo language was used as a secret code by the U.S. military. The code was unbreakable because it was spoken by only a small group of people who had been specially trained.

The Voynich Manuscript Code: The Voynich Manuscript is a mysterious book that was written in the 15th century. The book is written in an unknown language and contains strange illustrations, leading many to believe it is a code of some kind.

The Code of Hammurabi: The Code of Hammurabi is one of the oldest known codes of law. It was created in ancient Babylon around 1754 BC and contains 282 laws.

The Enigma Code: The Enigma Code was used by the Germans during World War II to encrypt their messages. The code was eventually broken by Alan Turing and his team, which helped to turn the tide of the war in favor of the Allies.

The Zodiac Killer Code: The Zodiac Killer was a serial killer who operated in California during the late 1960s and early 1970s. He sent encrypted messages to the police and newspapers, some of which have never been solved.

The Book of Soyga Code: The Book of Soyga is a mysterious book that was written in the 16th century. The book is written in code and contains information on topics such as astrology and alchemy.

The Caesar Cipher: The Caesar Cipher is one of the simplest codes in existence. It was used by Julius Caesar to encrypt his messages and works by shifting each letter in the alphabet a certain number of places.

The Beale Ciphers: The Beale Ciphers are a set of three ciphertexts that were published in the 19th century. The ciphertexts are believed to contain information on the location of a buried treasure, but they have never been deciphered.