Racal MA 4245 Pocket Cipher Device

The device was made by Racal Datacom Limited
Mitford Industrial Estate,
Tollgate Road,
Wiltshire UK

Dimensions are 170 mm x 114 mm x 64 mm
Weight: 1.1 kg.
Power: Works with  built-in nickel cadmium battery,  or external power supply. The charging time for a fully discharged battery is 14 hours. One charge lasts 10 hours under normal usage.
Temperature range:  From -10 to +55°C . Can be stored in temperatures from  -40 to +70°C.
Original cost 30,000 DM.
Vintage: 1979
Comment: It is water resistant and ruggedized for military use. Portability is the most important feature of this pocket cipher device.


The input is made via the keyboard and the output via a display with 2 digits. It can also support operation with a  MA 4233 printer.  For on-line operation, the MA
4245 needs to have an adapter.


 High security is generated by a computer program with 10 16 nonlinear key sequences, each with a length of 10 12 characters. The MA 4245 essentially consists of an alphanumeric Touch panel, the  dot matrix LED display together with the integrated semiconductor memory and control electronics.

The operation of the device consists of selecting the operating mode (encryption or decryption), a one-time basic key to set, from the 10 21 possibilities. If the full message has been entered, one can check it by use of the EDIT mode

M4245 - External view. 
M4245 - Underside view
M4245 - Arrangement of RAM, ROM and UART IC's. 
All M4245 photos in this table by Jörg Drobick


Contributors and Credits:

1) Jvörg Drobick <joerg.drobick(at)kabelmail.de>

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 Aug 25/23