Juno is a system with a machine from 1972. The East German Stasi and the army used it to change letters into numbers to send secret messages.

How did Juno start?

Juno was invented and made in 1972 by the factory VEB Kombinat Zentronik in the city of Sömmerda. The factory built the T-305 machine (Juno) to make the work of the Stasi easier. Before that, agents had to change letters into numbers by hand, but with this machine, it happened automatically.

The machine was made specifically to fit the T-304 Leguan. That was a device used since 1967 to keep messages secret. By using the new Juno machine and the T-304 together, the secret service of the GDR could send messages faster and without mistakes.

What is Juno?

Juno works in two steps to make a message secret. In the first step, a machine changes the letters into numbers. This happens with a table. Letters that are used often get one number, and other letters get two numbers. If there are regular numbers in the text, you always write them three times in a row. For words the secret service used often, there were special codes of five numbers.

In the second step, another machine makes the message extra safe. This machine adds random numbers to the numbers from the first step. There is a special math rule: if the sum is ten or more, you only write down the last number. For example, 6+7 becomes a 3. The result is a list of numbers sent in groups of five. The person who receives the message does exactly the same but the other way around to read the text again.

The Juno function

In GC Wizard, you can find this function in the folder Encryption and Codes → Juno.

How does the function work?

The Juno tool changes text into a code or turns the code back into regular text, possibly with an extra number key.