This is a digital replica of a 1940s NEMA machine. The NEMA machine was a 10-wheel
rotor machine designed by the Swiss army during the Second World War as a replacement for their Enigma
machines.
It is designed to encrypt messages using a specified configuration and key. The Swiss army would have predetermined configurations and keys for given days. Ciphers (encrypted messages) sent to their allies could then be decrypted by typing them into another machine with the same configuration and key, leaving the enemy with just a garbled cipher. Have a go yourself!
The configuration of the machine is made up by which rotors are plugged in and in which order. In this replica this has been set to "15-C / 12-A / 14-D / 13-B" (the rotors at either end are always the same, leaving 8 to be configured).
The key is the string of letters visible at the bottom of the rotors (determining their position). Have a go at setting your key, write it down but remember, don't let the enemy see it!
Once your key has been set, type in your message using your physical keyboard. Your cipher will appear on the notepad up top.
Once finished, take a note of your cipher, then reset the counter back to 0 on the right. Set your key again, then type in the cipher. Your original message will be revealed on the notepad.
This app was written for educational purposes by Alma, sponsored by Rapid7. It's best used on non-mobile devices.
It is designed to encrypt messages using a specified configuration and key. The Swiss army would have predetermined configurations and keys for given days. Ciphers (encrypted messages) sent to their allies could then be decrypted by typing them into another machine with the same configuration and key, leaving the enemy with just a garbled cipher. Have a go yourself!
The configuration of the machine is made up by which rotors are plugged in and in which order. In this replica this has been set to "15-C / 12-A / 14-D / 13-B" (the rotors at either end are always the same, leaving 8 to be configured).
The key is the string of letters visible at the bottom of the rotors (determining their position). Have a go at setting your key, write it down but remember, don't let the enemy see it!
Once your key has been set, type in your message using your physical keyboard. Your cipher will appear on the notepad up top.
Once finished, take a note of your cipher, then reset the counter back to 0 on the right. Set your key again, then type in the cipher. Your original message will be revealed on the notepad.
This app was written for educational purposes by Alma, sponsored by Rapid7. It's best used on non-mobile devices.
