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Printing Pocket Cipher Calculator - wanted item

The PPC-19 was the very first cipher machine developed by Klaus-Peter Timmann in the late 1970s, shortly after he had established his own company Tele Security Timmann (TST) in Pöcking (Germany). It had a built-in thermal printer and was suitable for the encryption of numbers only.

The device was based on one of the earliest portable calculators with built-in thermal printer from Hewlett Packard (HP): the HP-19C, shown in the image on the right [2]. It was introduced by HP in 1975 and was modified by Timmann for use as an encryption/decryption device. It could however still be used as a scientific calcuator.

The PPC-19 used a cipher algorithm of mixed congruential type in order to provide good stochastic distribution and security [1]. It had a key-length of 108 which was entered as a 10-digit number before use. As the device was only suitable for the encryption and decryption of numbers, the operator had to use a converion table to convert the text to numbers first.

When typing, the numbers were instantly encrypted and presented on the red 7-segment display. In addition, the output could be printed.
Three quarter view of the HP-19C that was used as the base for the PPC-19. Copyright David Hicks [2].

The HP-19C belonged to the first generation of HP calculators with Continuous Memory, which means that the stored program was not lost when the device was switched off. The PPC-19 was available in 1980 at a price of US$ 890 [1], whilst the price of the bare HP-19C was US$ 345 at the time [2].

Similar products
When microprocessors became available in the mid-1970s, TST was not the only one to develop an electronic pocket-size cipher machine. Similar (but not identical) devices were made by Mils Elektronic in Austria, who developed the PCCM-4000 and Datotek in the US, who made the slightly bigger DH-26. However, TST was the only one to base it on an existing pocket calculator.

Mils PCCM-4000 (late 1970s)
Datotek Inc (Texas, USA)
Help required
This page currently acts as a placeholder for information about the PPC-19 pocket cipher machine. If you have any additonal information, such as a manual, a brochure, or -better- an original PPC-19 device, please contact us. Your help is much appreciated.

  1. Louis Kruh, Cipher Equipment TST 1221
    Cryptologia, Volume 4, Issue 4, October 1980. p. 225.

  2. David G. Hicks, Images of HP-19C calculator
    MoHPC, Museum of HP Calculators, Copyright 1995-2013. Retrieved July 2013.
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