The price of security: A detailed comparison of the TLS handshake performance on embedded devices when using elliptic curve cryptography and RSA

Abstract

The Transport Layer Security (TLS) Protocol is the current de-facto standard for secure connections over an insecure medium; it combines asymmetric and symmetric cryptography to achieve authentication, confidentiality and message integrity. The flexibility of the TLS protocol regarding the algorithms used allows it to also run efficiently on mobile devices severely constrained in terms of available memory, computing power and energy. In this work we present a thorough performance evaluation of the TLS handshake process by breaking it down into its individual phases, with a focus on the comparison between the usually applied RSA algorithm and cryptographic primitives based on Elliptic Curve Cryptography (ECC). We are especially interested how the transition to more secure TLS cipher suites (like switching from one-way to mutual authentication or to ephemeral primitives) affects the load that is put on client and server when using RSA and ECC, respectively. © 2012 Springer-Verlag.