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PolarSSL Rebranded as "ARM mbed TLS" After Acquisition

ARM Acquires IoT Security Firm Offspark

UK-based Semiconductor technology firm ARM Ltd. announced on Monday that PolarSSL, the open source Transport Layer Security (TLS) solution for software and embedded devices, has been rebranded as “ARM mbed TLS”.

The news comes after ARM quietly acquired Offspark, the company behind PolarSSL, back in November 2014.

PolarSSL is a popular TLS solution used in many embedded devices, including sensor modules, communication modules and smartphones, as well as other “Internet of Things” (IoT) devices. The solution is also used in several major projects, including OpenVPN, OpenVPN-NL (a version of OpenVPN made by Fox-IT for the Dutch government), PowerDNS, the Hiawatha and Monkey HTTP Server web servers, and various commercial products.

While the terms of the acquisition were not disclosed, an ARM spokesperson described the deal to SecurityWeek as a “small scale acquisition” and that two employees from Offspark would become part of ARM.

According to ARM, the technology will remain open source and will be made available to developers for commercial use and help developers to design and build IoT products with enhanced communication security and software cryptography.

“As part of the mbed ecosystem, mbed TLS will provide the core for secure communications and cryptography to the rest of the mbed products. Although the mbed ecosystem is primarily targeted at the world of the Internet of Things (IoT), this does not mean that from now on mbed TLS will only work on ARM chipsets or IoT devices,” ARM’s Paul Baker explained in a blog post. “mbed TLS will continue on the existing path and stay available and operate on regular embedded and non-embedded systems, just like PolarSSL today.”  

ARM mbed TLS will be available for standalone use and as part of ARM’s mbed OS, the company said. ARM will release mbed OS under an Apache 2.0 license which will include mbed TLS, Thread, and other key technologies toward the end of 2015.

The release of mbed TLS 1.3.10, is now available under GPL and to existing PolarSSL customers on

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For more than 10 years, Mike Lennon has been closely monitoring the threat landscape and analyzing trends in the National Security and enterprise cybersecurity space. In his role at SecurityWeek, he oversees the editorial direction of the publication and is the Director of several leading security industry conferences around the world.