Highly secure voice communications via VoIP and SCIP
Wiretapping is pointless

The end of ISDN is dragging on a little, but that does not change the fact that the digital telephony standard has had its day. In the near future, German network operators will switch off the ‘Integrated Services Digital Network’ introduced in 1989 and IP telephony will then finally take its place. This poses a challenge for public authorities that depend on secret voice communications, as ISDN-based encryption systems are still used for this purpose across the board. With the SINA Communicator H, secunet now offers a compact, easy-to-use desktop solution that makes IP telephony highly secure – up to the SECRET classification level.

In Germany, telephony encryption solutions based on the ISDN standard are currently still used in public administration and by the German Armed Forces, in particular. In order to extend the life of these solutions, some rely on ISDN IP gateways. However, since the two underlying technologies, ISDN and IP, are very different – ISDN is line-oriented, while IP is packet-oriented – there are compatibility problems that can never be completely eliminated. Gateway solutions can facilitate the transition, but they will have to be replaced by new security technology specifically designed for IP telephony in the medium term.

secunet first took up this challenge several years ago. It was clear on what a new solution could be based: the SINA security architecture, which secunet had developed on behalf of the German Federal Office for Information Security (BSI), is essentially a concept for securing IP-based networks. In the meantime, SINA has proven itself over many years in numerous federal and state authorities and has become the leading security architecture in the Federal Republic of Germany. SINA is also used in other countries. A variety of versions are available for different application scenarios and security requirements, with German and international approvals for classification levels from RESTRICTED to SECRET.

With SINA Communicator H, users can easily switch between different levels of secrecy.

On this basis, secunet developed a highly secure telephony solution for the post-ISDN era: the SINA Communicator H. Designed as a desktop device in telephone format, the solution can be used for voice and data communication and is capable of being approved for the German classification level GEHEIM and its international equivalents (SECRET). The SINA Communicator H can be operated both within public authority networks and directly over the internet. It uses proven internet standards for Voice over IP (VoIP), supporting existing, commercially procured session initiation protocol (SIP)-capable switching infrastructures. In addition, it implements NATO protocols such as the Secure Communication Interoperability Protocol (SCIP), thus enabling secure communication with international allies.

Thanks to SINA Communicator H’s multi-level capability, users can easily switch between different security classification levels, such as VS-NfD, VS-VERTRAULICH and GEHEIM in the German national environment, and RESTRICTED, NATO SECRET or EU SECRET/ SECRET UE in the international environment. Native telephone calls can also be answered. “The SINA Communicator H combines the requirements of secret voice communication with the everyday practices of our modern working lives,” says Jan Leduc, Senior Product Manager at secunet. “With this solution, we have once again shown that high security and user-friendliness do not have to be mutually exclusive. As soon as a user has authenticated themselves with a security token and PIN, the solution’s functions can be accessed via convenient touch-screen controls.”

The 10.1-inch display enables numerous other applications in addition to pure voice communications. Text communications, video telephony and even thin-client functionality – with an optional external monitor – are all planned for later expansions, for instance. Further applications can be added as required, such as web clients, operational fax support, file and document exchange or multi-party messaging.

The migration of ISDN solutions to SINA Communicator H is also a worthy endeavour for public authorities, because the new telephony solution can be functionally integrated into existing SINA installations. “Today, it is already possible to communicate with SINA Workstation S and H via a secure IPsec connection at the GEHEIM (SECRET) level using VoIP,” explains Leduc. “This function can also be integrated into SINA Communicator H, making it backwards compatible with the VoIP applications of SINA Workstation S and H. Central administration via SINA Management, which is usually already used by public authorities, also increases efficiency and facilitates migration. Overall, our goal was to give our customers as much added value as possible with the SINA Communicator H – and in my opinion, we have achieved our goal.”

Contact request


Jan Leduc
secunet Security Networks AG

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secuview is the online magazine of secunet, Germany's leading cybersecurity company. Whether cloud, IIoT, home office, eGovernment or autonomous driving - there can be no digitisation without security.

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