Cooperative intelligent transport systems promise considerable improvements on road safety and the utilization of transport infrastructures. Current approaches, however, build upon policies to protect privacy, which raise serious concerns. In this paper, we propose a privacy-preserving public key infrastructure (PKI) for vehicle-to-everything communication. We use zero-knowledge proofs to authenticate, while still being able to hide identities. In order to exclude malicious actors, we integrate an anonymous reputation-based blacklisting scheme. Our benchmarks on an on-board connectivity unit with resource-constrained hardware confirms the feasibility of the approach. Specifically, we expect approximately 67 kB payload and 35 minutes computation time per day to authenticate.

This paper presents setup and results of a long-term outdoor range experiment carried out in a real environment. The objective was to explore long-range wireless communication in sub-GHz license-free radio bands, i.e., 169, 433, and 868 MHz under more realistic conditions. Not only transmission range, but also packet loss and received signal strength were evaluated. A large set of radio configurations was used to study the impact of transmission power, bit rate, and packet size. Also, the relationship between packet loss and received signal strength was investigated. A model could be developed that can help determine the expected packet loss rates as a function of the radio configurations and measured RSSI values.

An integration concept for an implantable biosensor for the continuous monitoring of blood sugar levels is presented. The system architecture is based on technical modules used in cardiovascular implants in order to minimize legal certification efforts for its perspective usage in medical applications. The sensor chip operates via the principle of affinity viscometry, which is realized by a fully embedded biomedical microelectromechanical systems (BioMEMS) prepared in 0.25-µm complementary metal–oxide–semiconductor (CMOS)/BiCMOS technology. Communication with a base station is established in the 402–405 MHz band used for medical implant communication services (MICS). The implant shall operate within the interstitial tissue, and the hermetical sealing of the electronic system against interaction with the body fluid is established using titanium housing. Only the sensor chip and the antenna are encapsulated in an epoxy header closely connected to the metallic housing. The study demonstrates that biosensor implants for the sensing of low-molecular-weight metabolites in the interstitial may successfully rely on components already established in cardiovascular implantology.

Side channel and fault attacks take advantage from the fact that the behavior of crypto implementations can be observed and provides hints that simplify revealing keys. In a real word a lot of devices, that are identical to the target device, can be attacked before attacking the real target to increase the success of the attack. Their package can be opened and their electromagnetic radiation and structure can be analyzed. Another example of how to improve significantly the success rate of attacks is the measurement of the difference of the side channel leakage of two identical devices, one of these devices being the target, using the Wheatstone bridge measurement setup. Here we propose to individualize the electrical circuit of cryptographic devices in order to prevent attacks that use identical devices: attacks, that analyze the structure of devices identical to the target device in a preparation phase; usual side channel attacks, that use always the same target device for collecting many traces, and attacks that use two identical devices at the same time for measuring the difference of side-channel leakages. The proposed individualization can prevent such attacks because the power consumption and the electromagnetic radiation of devices with individualized electrical circuit are individualized while providing the same functionality. We implemented three individualized ECC designs that provide exactly the same cryptographic function on a Spartan-6 FPGA. These designs differ from each other in a single block only, i.e. in the field multiplier. The visualization of the routed design and measurement results show clear differences in the topology, in the resources consumed as well as in the power and electromagnetic traces. We show that the influence of the individualized designs on the power traces is comparable with the influence of inputs. These facts show that individualizing of electrical circuits of cryptographic devices can be exploited as a protection mechanism. We envision that this type of protection mechanism is relevant if an attacker has a physical access to the cryptographic devices, e.g. for wireless sensor networks from which devices can easily be stolen for further analysis in the lab.

Side channel and fault attacks take advantage from the fact that the behavior of crypto implementations can be observed and provide hints that simplify revealing keys. These attacks use identical devices either for preparation of attacks or for measurements. By the preparation of attacks the structure and the electrical circuit of devices, that are identical to the target, is analyzed. By side channel attacks usually the same device is used many times for measurements, i.e. measurements on the identical device are made serially in time. Another way is to exploit the difference of side channel leakages; here two identical devices are used parallel, i.e. at the same time. In this paper we investigate the influence of the electrical circuit of a cryptographic implementation on the shape of the resulting power trace, because individualizing of circuits of cryptographic devices can be a new means to prevent attacks that use identical devices. We implemented three different designs that provide exactly the same cryptographic function, i.e. an ECC kP multiplication. For our evaluation we use two different FPGAs. The visualization of the routed design and measurement results show clear differences in the resources consumed as well as in the power traces.

Side channel and fault attacks take advantage from the fact that the behavior of crypto implementations can be observed and provide hints that simplify revealing keys. These attacks are normally prepared by analyzing devices that are identical to the real target. Here we propose to individualize the design of cryptographic devices in order to prevent attacks that use identical devices. We implemented three different designs that provide exactly the same cryptographic function, i.e. an ECC kP multiplication. The synthesis and power simulation results show clear differences in the area consumed as well as in the power traces. We envision that this type of protection mechanism is relevant e.g. for wireless sensor networks from which devices can easily be stolen for further analysis in the lab. Keywords— cryptographic hardware architectures, security processors, countermeasures against side-channel attacks

In this paper we describe a sensor node crypto processor designed for use in wireless sensor networks with strong security demands. The presented system-on-chip is a mixed-signal processor-based design containing the hardware crypto accelerators (AES, ECC, SHA-1) that provide the means for secure communication in the network. The unique system architecture combines an asynchronous processor core with synchronous peripherals resulting in a low-power system operation. The designed chip integrates an embedded Flash memory and a 12-bit ADC making it a suitable solution for small-size sensor node devices. The paper describes the chip architecture and discusses the most important implementation and verification issues. Finally, the results of the chip measurement have been presented.

A path loss determination for 403 MHz MICS band antennas based on measurements in body phantom liquid is presented. Suitable antennas were identified that can be used in medical implants. A reproducible measurement setup has been tested that allows for a quantitative comparison of different implant antennas.

This paper presents the path loss estimation for 433 MHz waves transmitted from inside an algae culture. Investigations were performed as preliminary consideration for a biochemical sensor capsule application. It was found that the path loss in distilled water on average was 15 dB higher than in air. The path loss in algae was 6 dB higher than in water. The differences were caused by a mismatch of the transmit antenna surrounded by a liquid medium.

INTRODUCTION Wireless sensor networks (WSNs) are becoming an essential building block in application fields such as critical infrastructure protection, industrial automation, environmental monitoring and telemedicine to name a few areas of some importance to our societies. The major challenges in all these applications are achieving a long lifetime of the sensor network and guaranteeing kind of quality of service. While the latter – in most cases can be interpreted as short reaction timesleading to higher energy consumption the former asks for low power approaches such as duty cycling. In order to cope with these contradicting demands a holistic approach for the design of a single sensor node but also for a complete network are essential. By holistic approach we mean that the complete system shall be developed as a complete item consisting of maybe specialized hardware and software, which is infeasible when relying on components of the shelf (COTS).

The theoretical evaluation of an implantable system measuring glucose for diabetes diagnostics and therapy has recently been presented. This work reports on the realisation of the proposed system on a printed circuit board and measurements of its energy budget. It is shown that the system can be run with small 3.2 V batteries for more than six months with an average energy consumption of 0.12 mAh.

The security emerges as a very important constraint for many wireless sensor network applications. This paper presents the design of a sensor node processor supported by a variety of security mechanisms including complex data cryptography and hash generation. Additionally, the processor core is enhanced with the hardware acceleration for IEEE 802.15.4 medium access layer operations. The paper describes the chip architecture and its components and gives the chip implementation details. Finally, the power and performance of the chip have been discussed and analyzed.

In this paper we present a sensor node processor designed to support complex data encryption/decryption operations. The system is developed around an asynchronous processor core supported by AES, ECC and SHA-1 crypto accelerators. The paper describes the chip architecture and its components and gives the chip implementation details. Finally, the power and performance of the chip have been discussed and analyzed.

Modern, energy-efficient sensor nodes cover a wide variety of application scenarios. For a fast adapting of these devices to new requirements a concurrent development process of software and hardware extensions must be feasible. Here we present a Hybrid Simulation Environment (HSE) that combines a cycle accurate simulator for MSP microcontrollers written in Java and SystemC, which allows description of hardware at reasonable abstraction level. The HSE significantly speeds up the simulation of new components compared to conventional simulation engines.

This paper presents a low power solution for sensor node processor architecture, where an asynchronous processor has been integrated with a number of peripherals in a quite unique fashion. The paper describes the most important architectural and design issues and presents the implementation results.