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TopSec Mobile
Smartphone voice encryptor - this page is a stub

TopSec Mobile is a mobile encryption device, introduced in 2008 by Rohde & Schwarz SIT 1 in München (Munich, Germany). It enables secure (tap-proof) voice calls via GSM and UMTS mobile net­works, using AES-256 encryption via a Bluetooth® connection. It is the successor to the less secure TopSec GSM, and is compatible with iPhone, Android, Windows Phone and Windows PC. It is certified by the BSI and NATO/SECAN for coversations up to the level of VS-VERTRAULICH [4]. 2

The product consists of two parts: a software-based VoIP client for the mobile phone, and an external hardware-based encryption unit that connects to the mobile phone via Bluetooth.

The VoIP client is available from R&S as a free App for most smartphones and can also be used as a stand-alone application for making normal (insecure) VoIP calls. For secure conversations, the external TopSec Mobile device is needed, as shown in the image on the right.

Encryption and decryption are entirely handled by the device. Keys are exchanged by means of a 384-bit ECC algorithm, whilst AES-256 is used for the transmission of the actual voice data [2]. Furthermore, it uses its own microphone and earphones, so that no unencrypted voice data is handled by the mobile phone itself.

Two (mobile) parties can exchange secure calls, if they both have installed a TopSec Mobile unit and the accompanying application (App). In addition, secure calls to regular VoIP telephones can be made when the external party has installed a TopSec Office Gateway (TSOG) on its PABX [H].

TopSec Mobile is certified by the German Federal Office for Information Security (BSI) and NATO/SECAN, for conversations up to the level of VS-VERTRAULICH [4].

  1. Rohde & Schwarz SIT is a subsidary of Rohde & Schwarz Cybersecurity GmbH, whicht itself is a subsidary of Rohde & Schwarz International GmbH (RUSIG). Both companies are located at the same premises.
  2. VS-VERTRAULICH = Vertrouwliche Verschlusssache — equivalent to CONFIDENTIAL [6].

Promotional video by Rohde & Schwarz, published on YouTube in October 2015 [5]

 Same video clip with German voice-over

  • Bluetooth
  • Protocol
    V.32, V.110, TCP/IP
  • Standby
    100 hours
  • Usage
    4 hours
  • Data transfer
    3G, EDGE, Wi-Fi
  • Data rate
    9600 bit/s
  • Controls
  • Readout
    Liquid Crystal Display (LCD)
  • Support
    (see below)
  • Authentication
    384-bit ECC key exchange
  • Encryption
    256-bit AES encryption
  • Weight
    85 grams
  1. TopSec Mobile (device) — user manual (German)
    5411.1567.03-05.01. Rohde & Schwarz GmbH, 2015.

  2. TopSec Mobile Phone App for iOS — user manual (English)
    5415.5050.02. Rohde & Schwarz SIT GmbH, 2012.

  3. TopSec Mobile & TopSec Phone Windows PC — user manual (English)
    Rohde & Schwarz SIT GmbH, 2013.

  4. TopSec Mobile & TopSec Phone Windows PC — user manual (German)
    Rohde & Schwarz SIT GmbH, 2013.

  5. TopSec Mobile, tap-proof phone calls — brochure
    PD 3606.6492.12. Rohde & Schwarz GmbH & Co. KG, February 2014. Version 03.00.

  6. Smart and secure: tap-proof voice calls on smartphones
    Erika Friesen. R&S News 207/12 pp. 43-45.

  7. TopSec Office Gateway, Festnetzgegenstellen — Specifikationen
    Rohde & Schwarz SIT GmbH, 2014.
  1. Tim Ehrhart, two R&S TopSec Mobile devices - THANKS !
    Received October 2021.

  2. Peter Koop, Rohde & Schwarz: TopSec Mobile 22 June 2012. Updated 9 April 2016.

  3. Feature comparison between Stealthphone Hard and TopSec Mobile
    Mobile Trust Telecommunications. Date unknown.

  4. BSI, Sicheres mobiles Arbeiten
    Bundesamt für Sicherheit in der Informationstechnik (BSI), October 2016. pp. 43-45.

  5. Rohde & Schwarz, TopSec Mobile - Tap-proof phone calls (video)
    Via YouTube. 1 October 2015 (English spoken).
     German version

  6. Wikipedia (Germany), Geheimhaltungsgrad
    Visited 26 September 2021.
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Crypto Museum. Created: Sunday 26 September 2021. Last changed: Wednesday, 27 October 2021 - 08:47 CET.
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