Military Communication – Code Talker Encryption

Military communication technology is constantly advancing, leading to increasingly specialized roles for soldiers operating communication systems, starting from just a single flag bearer. Following the entry into electronic warfare, the division of labor among communication soldiers became quite detailed.

For instance, a Voice Communication Soldier is responsible for transmitting signals, while a Code Translation Soldier (or Crypto Soldier) is responsible for receiving signals. Although these are distinct functions within the system, in real combat situations, such formalities are often disregarded, and both voice communication and translation are handled by the same soldier. This role often involves intense mental strain, requiring the memorization of numerous codes to prevent communication content from being intercepted.

Devising codes that the enemy cannot break is a military imperative. During World War II, Germany used the Enigma machine aboard U-boats. Their unpredictable movements sank a large number of Allied ships in the Atlantic, causing British Prime Minister Winston Churchill great alarm.

Today, the development of an "AI Code Talker" system, which uses Natural Language AI technology to simulate a communicator's biometric characteristics and speaking traits as an encryption key, is an interesting area of study. The concept of customizing a communicator's characteristics to serve as an encryption key has long been adopted by the military, known as the "Code Talkers" encryption. Code Talkers were essentially the Voice/Code Translation Soldiers, but the difference was that they acted like members of secret Chinese gangs of the past, who would speak in a "gang dialect" (幫派切口) when discussing secrets among brothers, making it incomprehensible to outsiders. During the Sino-Japanese War, the Qing Dynasty used Wenzhounese as a form of encryption. In World War I, the US successfully attacked German forces by using the Choctaw Native American language to transmit secret military messages. Germany and Japan learned this lesson and sent many students to the US after WWI to learn Native American languages such as Cherokee, Choctaw, and Comanche. The US military, upon discovering this, became concerned that Germany and Japan might be able to decrypt the messages and considered abandoning the "Code Talkers" system.

At this time, an engineer and WWI veteran, Philip Johnston, suggested encoding messages using the little-known Navajo language.

Johnston grew up in the Navajo Indian Reservation, interacted with the Navajo people, and was familiar with their language and customs. The complex structure of the Navajo language made it more suitable for encryption than the previously used Native American languages. After Johnston's demonstration, the US Marine Corps decided to adopt the proposal, immediately recruiting 29 Native Navajo men to begin the coding work, using a total of 411 vocabulary words. The Marine Corps implemented a second layer of encryption on top of the first coding layer using Word Substitution. For example, the Navajo word "Gini" translates to "Chicken Hawk" in English, but the actual military term it represented was "Dive Bomber."

During WWII, the US employed a total of 400 Navajo Code Talkers. This code was never broken until the end of the war. Ironically, in 1861, white Americans first used flag-based communication in battles against the Navajo, only to rely on the Navajo people to assist US military communication and be integrated into the US Marine Corps during World War II.

The 2002 film "Windtalkers" tells the story of the Navajo Code Talkers during the Battle of Saipan in the Pacific in 1944. This movie highlights a fundamental human dilemma. The military must protect the "encryption/decryption machine" at all costs, but when there is a risk of the Code Talker—the "human encryption/decryption machine"—falling into enemy hands, they must be preemptively destroyed. How could a comrade ordered to execute this destruction carry out the command? This contradiction becomes the central focus of the film's interpretation.

Current technological advancements have enabled the automation and digitization of encryption, eliminating the need for human intervention. However, utilizing Natural Language Artificial Intelligence (AI) technology to simulate a communicator's biometric characteristics and speaking traits as an encryption key—could this strengthen the effect of encryption? The development of AI Code Talker systems is a compelling area. By applying natural language processing and machine learning techniques, AI can simulate a communicator's biometrics and speaking style, becoming the key to encryption.

Nevertheless, establishing a comprehensive and secure Code Talker system requires a deep understanding of specific languages, dialects, and cultural backgrounds. Furthermore, developing robust and secure communication systems requires considering factors that extend beyond what can be achieved through text-only interaction. Currently, the development of AI Code Talker systems still requires more research and effort.

 

Dr. Jason Yi-Bing Lin

Lifetime Chair Professor of the Department of Computer Science at National Yang Ming Chiao Tung University and Winbond Chair Professor Dr. Lin is currently a lifetime chair professor of the Department of Computer Science at National Yang Ming Chiao Tung University and Winbond chair professor. He is an ACM Fellow, IEEE Fellow, AAAS Fellow and IET Fellow. His research interests include Internet of Things, mobile computing, and system simulation. He has developed an Internet of Things system called IoTtalk, which is widely used in smart agriculture, smart education, smart campus, and other fields. He has a variety of interests, such as art, painting, and writing, as well as voyaging through science, technology, and humanities.