What is 535 and how do you use this function?

How did code 535 originate?

Code 535 (also known as 50010) is a manual digit system from 1980 that the East German border troops used to send secret messages during the Cold War.

What is code 535?

The system used a clever digit table, also called a Straddling checkerboard. With this table a soldier could very quickly convert letters into short numbers. To make the message truly secret, a one-time digit code (One-Time Pad) was added. Because this extra code was destroyed after a single use, the message was impossible for outsiders to crack. This allowed soldiers in the field to send messages without complicated equipment that even the strongest computers could not read.

The 535 function

In GC Wizard you can find this function in the folder Encryption and Codes → 535

How does the function work?

At the top of the screen there is a text field. Here you enter the text or digit sequence that needs to be encrypted or decrypted.
Below that there is a slider, Instelling. With this you indicate whether the entered text or digit sequence should be encrypted (Encrypt) or decrypted (Decrypt).

Encrypt

If you choose Encrypt, the text will be encrypted into a digit sequence.

OTP key

Below the Instelling there is a slider OTP key. With this you indicate whether you want to use an OTP Key. This is the One Time Pad key.

If you enable this option, a text field will appear. Here you enter one or more numbers.

Output

Under Output the encrypted text appears in the form of a sequence of numbers.

Behind this text there is a copy button with which you can copy this digit sequence to the clipboard.

Decrypt

If you choose Decrypt, the digit sequence will be decrypted into text.

OTP key

Below the Instelling there is a slider OTP key. With this you indicate whether you want to use an OTP Key. This is the One Time Pad key.

If you enable this option, a text field will appear. Here you enter one or more numbers.

Output

Under Output the decrypted text appears.

Behind this text there is a copy button with which you can copy this text to the clipboard.