Kris Aerts

Two for the Price of One? On Additionality Effects of R&D Subsidies: A Comparison between Flanders and Germany

In this paper we empirically test whether public R&D subsidies crowd out private R&D investment in Flanders and Germany, using firm level data from the Flemish and German part of the Community Innovation survey (CIS III and IV). Both the non-parametric matching estimator and the conditional difference-in-difference estimator with repeated cross-sections (CDiDRCS) clearly indicate that the crowding-out hypothesis can be rejected: funded firms are significantly more R&D active than non-funded firms. In the domain of additionality effects of R&D subsidies, this paper is the first to apply the CDiDRCS method.

Using Innovation Survey Data to Evaluate R&D Policy: The Case of Belgium

This study focuses on the impact of R&D policies in Flanders. We conduct a treatment effects analysis at the firm level to investigate possible crowdingout effects on the input side of the innovation process. Different specifications of R&D activity are considered as outcome variables in the treatment effects analysis. Applying a non-parametric matching, we conclude that subsidized firms would have invested significantly less in R&D activities, on average, if they had not received public R&D funding. Thus, crowding-out effects can be rejected in this case.

A Fast and Compact FPGA Implementation of Elliptic Curve Cryptography Using Lambda Coordinates

Elliptic curve cryptography ECC provides high security with shorter keys than other public-key cryptosystems and it has been successfully used in security critical embedded systems. We present an FPGA-based coprocessor that communicates with the host processor via a 32-bit bus. It implements ECC over an elliptic curve that offers roughly 128-bit security. It is the first hardware implementation that uses the recently introduced lambda coordinates and the Galbraith-Lin-Scott GLS technique with fast endomorphisms. One scalar multiplication requires 65,000 clock cycles with a maximum clock frequency of 274i¾?MHz on a Xilinx Virtex-5 FPGA, which gives a computation time of 0.24i¾?ms. The area utilization is 1552 slices and 4 BlockRAMs. Our coprocessor compares favorably to other published works both in terms of speed and area, which makes it a good choice for embedded systems that rety public-key cryptography.

Efficient Key Pre-distribution for 6LoWPAN

The Internet of Things is imposing an evolution of the capabilities of wireless sensor networks. The new IP-based 6LoWPAN standard for low power sensor networks allows an almost seamless connection of local sensor networks to the Internet. On the other hand, the connection to the Internet also opens doors for unauthorized nodes to become part of the local network. The most important challenge in preventing this, is the implementation of a key management architecture, keeping in mind that the sensor nodes are constrained in power consumption and data storage capacity. This paper builds on a previously proposed symmetric key management scheme for 6LoWPAN networks presented by Smeets et al.in [1]. The original scheme is based on wired bootstrapping for the enrollment of new nodes, while the paper at hand proposes a wireless method. We analyze the original wired scheme and propose an improved wireless scheme, elaborating on the practical implementation on Zolertia Z1 nodes running Contiki-OS. We show that it is possible to provide end-to-end security using wireless bootstrapping within the constraints of the tiny nodes at hand.

Design space exploration for automatically generated cryptographic hardware using functional languages

This paper presents an EDA (Electronic Design Automation) tool that generates basic building blocks for cryptographic hardware in VHDL. The purpose of the tool is to decrease the design time of cryptographic hardware and to allow designers to make abstraction of both the arithmetic and design complexity. The tool generates multiple implementations for one arithmetic description and then benchmarks the implementations to find the most optimal, based upon design space parameters. These parameters consist of area and speed requirements. We present datapath and control logic results for a Xilinx Virtex-5 FPGA. The novelty in our approach lies in the fact that we exploit the higher-order features of functional languages to facilitate the design space exploration and that we take benefit from the strength of the third-party synthesis tool by generating VHDL code at an abstraction level that is higher than the gate level. Nevertheless, in this stage of the development of the tool, the different cryptographic architectures are hand-made and the selection of the most optimal solution, based upon user requirements, is done by exhaustive search. This means that the tool leaves room for improvement, but forms a solid base for further development.

Visto: a more declarative GUI framework

By inverting the widget — call back relationship and by providing selectors, a suitable abstraction for concrete widget choices, Visto provides a more declarative approach to defining user interfaces, building on the declarativeness of the lazy functional language Haskell.

A cryptographic key management architecture for dynamic 6LowPan networks

Wireless sensor networks are becoming an important facilitator for the Internet of Things. These embedded devices can harvest dierent types of information such as temperature, pressure and humidity, which oer important data for making decisions regarding various applications such as healthcare, logistics and smart homes. Dierent sensors working together act as a local sensor network. With the advent of the new 6LowPan standard the sensor nodes can even participate in Internet communications, opening up even more possibilities. The downside is that these networks are more prone to intrusion by unwanted parties. Furthermore implementing security is not straightforward due to the constrained nature of the sensor nodes, although dierent solutions have been proposed. One of the remaining and most challenging issues is the key management problem. In this paper, we propose a symmetric key management scheme for wireless sensor networks that uses tamper-proof hardware for key generation and distribution. The scheme requires no deployment knowledge before enrolling and makes use of a trusted central entity for key negotiation to provide end-to-end security. Our implementation and evaluation were performed on the tiny Zolertia Z1 hardware platform, running Contiki-OS. The performance and security evaluation show This work is funded by the IWT-TETRA project 120105: 6LoWPAN - Towards zero

A GUI on top of a functional language (poster)

Functional programming has proved to be an uttermost declarative methodology. It focuses on the what and not on the how. Aleo 1/0 can be successfully expressed in FP, although rumour has it that none of the functional 1/0 systems really work as elegant aa functional languages can. In the field of graphical user interfaces (GUI), impressive results have been achieved. Two different but major milestones are the Fudgets library [1] in Haskell and the Clean 1/0 system [2]. Despite the fact that they are really successful, both systems suffer from the fact that they are not aa declarative aa could be, because they concentrate too much on the how. They require the programmer to first choose the actual form of the interface. This describes how the action is triggered, not what action. Only after the programmer has defined f,e. the button, can he attach functionality to it. Notice also that the application code must be attached to the button spectically. This means that changing from a button to a menu item mav incorporate suite some work: . . . the definition and type of the attached function may change or may be attached in a different way. This is too much focus on the how on the appearance of the widget. In ‘Selectors: going beyond user-interface widgets’ [3] Jeff Johnson describes how each element of a user interface serves one of two purposes: either to select data, or to select commands, e.g. a pull down menu can be used to start a command, such aa load and save, or also as a way ta limit the input possibtities for the user. This is the point we are really interested in: are we selecting commands or data (and what data)? Whether this ia dane through a pull dawn menu or a button list is irrelevant. The actual vieu al appearance is only part of the how. The observed division in data and command selectors is particularly applicable in imperative languages, because there a certain variable can be easily connected to a widget. And when the widget is selected, the contents of that variable will be (destructively) updated. Despite the fact that (pure) functional languages do not allaw such side effects. we believe that this can be accomplished by the use of state transition functians. The paster will present work in progress regarding the implementation of such ‘selectors’ using both Fudgets and Clean 1/0. Work