Despite realistic concerns, security is still absent from vehicular buses such as the widely used Controller Area Network (CAN). We design an efficient protocol based on efficient symmetric primitives, taking advantage of two innovative procedures: splitting keys between nodes and mixing authentication tags. This results in a higher security level when compromised nodes are in the minority, a realistic assumption for automotive networks. Experiments are performed on state-of-the-art Infineon TriCore controllers, contrasted with low-end Freescale S12X cores, while simulations are provided for the recently released CAN-FD standard. To gain compatibility with existent networks, we also discuss a solution based on CAN+.

In this work, elliptic curve cryptography (ECC) is used to make a fast, and very low-power software implementation of a public-key cryptography algorithm on the ARM Cortex-M0+. An optimization of the López-Dahab field multiplication method is proposed, which aims to reduce the number of memory accesses, as this is a slow operation on the target platform. A mixed C and assembly implementation was made; a random point multiplication requires 34.16 μJ, whereas our fixed point multiplication requires 20.63 μJ. Our implementation's energy consumption beats all other software implementations, on any platform, by a factor of at least 3.3.

The ability to generate secure random numbers is fundamental to the security of cryptographic protocols. Random Number Generators (RNGs) start to appear in recent modern Intel CPUs as used in desktops and servers. Solutions for embedded devices, such as e.g. sensor nodes and wireless routers, are still severely lacking however.

Research on Physically Unclonable Functions (PUFs) has become very popular in recent years. However, all PUFs researched so far require either ASICs, FPGAs or a microcontroller with external components. Our research focuses on identifying PUFs in commercial off-the-shelf devices, e.g. microcontrollers. We show that PUFs exist in several off-theshelf products, which can be used for security applications. We present measurement results on the PUF behavior of five of the most popular microcontrollers today: ARM Cortex A,ARM Cortex-M,Atmel AVR, Microchip PIC16 and Texas Instruments MSP430. Based on these measurements, we can calculate whether these chips can be considered for applications requiring strong cryptography. As a result of these findings, we present a secure bootloader for the ARM Cortex-A9 platform based on a PUF inherent to the device, requiring no external components. Furthermore, instead of discarding the randomness in PUF responses, we utilize this to create strong seeds for pseudo-random number generators (PRNGs). The existence of a secure RNG is at the heart of virtually every cryptographic protocol, yet very often overlooked. We present the implementation of a strongly seeded PRNG for the ARM Cortex-M family, again requiring no external components.