INTEGRATION OF HARDWARE SECURITY MODULES INTO A DEEPLY EMBEDDED TLS STACK

Abstract

The Transport Layer Security (TLS) protocol is a well-established standard for securing communication over insecure communication links, offering layer-4 VPN functionality. In the classical Internet TLS is widely used. With the advances of the Internet of Things (IoT) there is an increasing need to secure communication on resource-constrained embedded devices. On these devices, computation of complex cryptographic algorithms is difficult. Additionally, sensor nodes are physically exposed to attackers. Cryptographic acceleration and secure hardware security modules (HSMs) are possible solutions to these challenges. The usage of specialized cryptographic modules for TLS is not a new phenomenon. However, there are still few hardware security modules suitable for the use on microcontrollers in sensor networks. We therefore present an overview of HSM and TLS solutions along with sample implementations and share some recommendations how to combine both.