There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Wireless indoor positioning systems have become very popular in recent years. These systems have been successfully used in many applications such as asset tracking and inventory management. This paper provides an overview of the existing wireless indoor positioning solutions and attempts to classify different techniques and systems. Three typical location estimation schemes of triangulation, scene analysis, and proximity are analyzed. We also discuss location fingerprinting in detail since it is used in most current system or solutions. We then examine a set of properties by which location systems are evaluated, and apply this evaluation method to survey a number of existing systems. Comprehensive performance comparisons including accuracy, precision, complexity, scalability, robustness, and cost are presented.

Survey of Wireless Indoor Positioning Techniques and Systems

National Institute of Standards and Technology における超伝導研究及び生活

We present a new block cipher LED. While dedicated to compact hardware implementation, and offering the smallest silicon footprint among comparable block ciphers, the cipher has been designed to simultaneously tackle three additional goals. First, we explore the role of an ultra-light (in fact non-existent) key schedule. Second, we consider the resistance of ciphers, and LED in particular, to related-key attacks: we are able to derive simple yet interesting AES-like security proofs for LED regarding related- or single-key attacks. And third, while we provide a block cipher that is very compact in hardware, we aim to maintain a reasonable performance profile for software implementation.

The LED block cipher

In this paper we propose a new family of very efficient hardware oriented block ciphers. The family contains six block ciphers divided into two flavors. All block ciphers share the 80-bit key size and security level. The first flavor, KATAN, is composed of three block ciphers, with 32, 48, or 64-bit block size. The second flavor, KTANTAN, contains the other three ciphers with the same block sizes, and is more compact in hardware, as the key is burnt into the device (and cannot be changed).

The smallest cipher of the entire family, KTANTAN32, can be implemented in 462 GE while achieving encryption speed of 12.5 KBit/sec (at 100 KHz). KTANTAN48, which is the version we recommend for RFID tags uses 588 GE, whereas KATAN64, the largest and most flexible candidate of the family, uses 1054 GE and has a throughput of 25.1 Kbit/sec (at 100 KHz).

/pdf/katan-and-ktantan-a-family-of-small-and-efficient-hardware-1nbl4htw1x.pdf

KATAN and KTANTAN -- A Family of Small and Efficient Hardware-Oriented Block Ciphers

Increasing amount of Wireless Sensor Network (WSN) applications require low network delays. However, current research on WSNs has mainly concentrated on optimizing energy-efficiency omitting low network delays. This paper presents a novel WSN design targeted at applications requiring low data transfer delays and high reliability. We present the whole design flow from user requirements to an actual pilot deployment in a real hospital unit. The WSN includes multihop low-delay data transfer and energy-efficient mobile nodes reaching lifetime of years with small batteries. The nodes communicate using a low-cost low-power 2.4GHz radio. The network is used in a security application with which personnel can send alarms in threatening situations. Also, a multitude of sensor measurements and actuator control is possible with the WSN. A full-scale pilot deployment is extensively experimented for performance results. Currently, the pilot network is in use at the hospital.

/pdf/a-wireless-sensor-network-for-hospital-security-from-user-3hl8e1vig3.pdf

A wireless sensor network for hospital security: from user requirements to pilot deployment

High computational requirements combined with rapidly evolving video coding algorithms and standards are a great challenge for contemporary encoder implementations. Rapid specification changes prefer full programmability and configurability both for software and hardware. This paper presents a novel scalable MPEG-4 video encoder on an FPGA-based multiprocessor system-on-chip (MPSOC). The MPSOC architecture is truly scalable and is based on a vendor-independent intellectual property (IP) block interconnection network. The scalability in video encoding is achieved by spatial parallelization where images are divided to horizontal slices. A case design is presented with up to four synthesized processors on an Altera Stratix 1S40 device. A truly portable ANSI-C implementation that supports an arbitrary number of processors gives 11 QCIF frames/s at 50 MHz without processor specific optimizations. The parallelization efficiency is 97% for two processors and 93% with three. The FPGA utilization is 70%, requiring 28 797 logic elements. The implementation effort is significantly lower compared to traditional multiprocessor implementations.

/pdf/scalable-mpeg-4-encoder-on-fpga-multiprocessor-soc-1j3pclg27m.pdf

Scalable MPEG-4 encoder on FPGA multiprocessor SOC

Wireless Sensor Networks (WSN) are seen as attractive solutions for various monitoring and controlling applications, a large part of which require protection. Due to the special characteristics of WSNs, e.g. low processing and energy resources and ad hoc networking, developing a reliable security solution becomes a challenging task. In this paper we survey various security aspects of WSNs, consisting of threats, attacks, and proposed solutions. We also present experiments with our own WSN technology (TUTWSN), concentrating on a centralized key distribution and authentication service. Our experiments suggest that a centralized scheme can be a feasible solution in certain WSN configurations.

Security in wireless sensor networks : Considerations and experiments

Wireless Sensor Networks (WSN) are seen as attractive solutions for various monitoring and controlling applications, a large part of which require cryptographic protection. Due to the strict cost and power consumption requirements, their cryptographic implementations should be compact and energy-efficient. In this paper, we survey hardware architectures proposed for Advanced Encryption Standard (AES) implementations in low-cost and low-power devices. The survey considers both dedicated hardware and specialized processor designs. According to our review, currently 8-bit dedicated hardware designs seem to be the most feasible solutions for embedded, low-power WSN nodes. Alternatively, compact special functional units can be used for extending the instruction sets of WSN node processors for efficient AES execution.

Review of hardware architectures for advanced encryption standard implementations considering wireless sensor networks

Key challenge for embedded system companies is management of product configurations over lifecycle. Either new functionality is implemented on an old platform, legacy code on a new one, or both at the same time. We propose Kactus2, a product integration environment suitable for small and mid-size enterprises (SME) utilizing FPGAs. We combine IP-XACT for HW integration and Multicore Association Communications API (MCAPI) for SW integration. The programmer has a uniform view of the system as MCAPI nodes regardless of their implementation in SW or HW. Kactus2 is a work-in-progress open source project implemented in C++ and QT 4.7 currently containing over 40k lines of code and gSOAP as TGI IP-XACT interface.

Marko Hännikäinen

Papers

A wireless sensor network for hospital security: from user requirements to pilot deployment

Scalable MPEG-4 encoder on FPGA multiprocessor SOC

Security in wireless sensor networks : Considerations and experiments

Review of hardware architectures for advanced encryption standard implementations considering wireless sensor networks

Kactus2: Environment for Embedded Product Development Using IP-XACT and MCAPI