World’s first tap-proof mobile telephone now available

Tap-Proof Mobile Telephone

World’s first tap-proof mobile telephone now available

20.06.2001 - The TopSecGSM from Rohde & Schwarz SIT GmbH is the world’s first tap-proof mobile telephone. Based on the S35i mobile telephone from Siemens, which has been enhanced with a crypto module, the TopSecGSM allows the user to switch to crypto mode and thus carry out secure communications simply by pressing a button.

A combination of asymmetric 1024-bit encryption and a symmetric 128-bit algorithm offers the highest level of security. Decoding is just as likely as five times six winning numbers in the lottery. For encrypted transmissions, the TopSecGSM uses the GSM data channel. First, the station being called, which must also be a TopSec mobile telephone or have a TopSec box, is contacted for key exchange.
With each call, a 128-bit key is randomly determined out of 10 ³⁸ possibilities, and is securely transmitted by means of a 1024-bit encryption algorithm. The tap-proof connection is established in 10 to 15 seconds and also displayed.
The crypto telephone is of particular interest to companies, banks, authorities and governments, which would like to protect their mobile communications against unauthorized listeners. The TopSecGSM, which works in both GSM frequency ranges of 900 MHz and 1800 MHz, is available immediately from Rohde & Schwarz.