Modern, commonly used cryptosystems based on encryption keys require that the length of the stream of encrypted data is approximately the length of the key or longer. In practice, this approach unnecessarily complicates strong encryption of very short messages commonly used for example in ultra-low-power and resource-constrained wireless network sensor nodes based on microcontrollers (MCUs). In such cases, the data payload can be as short as a few bits of data while the typical length of the key is several hundred bits or more. The article proposes an idea of employing a complex of two algorithms, initially applied for data compression, acting as a standard-length encryption key algorithm to increase the transmission security of very short data sequences, even as short as one or a few bytes. In this article, we present and evaluate an approach that uses LZW and Huffman coding to achieve data transmission obfuscation and a basic level of security.

Development of FPGA-based, network-enabled embedded systems in Register Transfer Level hardware description languages is tedious. Despite the automation of this process with numerous EDA tools available, no well-established design patterns exist. Moreover, the entire production cycle requires appropriate theoretical background and hardware design intuition from the developer which discourages the software community. To improve productivity and minimize time to market when assembling such systems, we propose a new hardware/software co-design approach to building reconfigurable hardware web services. The proposed integrated development platform features a programmable FPGA board where computations of different nature and purpose are logically distributed among a sequential soft-core processor program, a massively parallel accelerator and an independent communication module that handles remote clients’ requests. Our second contribution is a set of tools that make the development of the aforementioned services essentially a software design undertaking with the extensive use of high-level programming languages. The platform has been tuned to act as a flexible runtime environment for image processing services, thus providing functionality of an intelligent camera. Two example services built from scratch according to the new methodology are discussed. Reduced development time and significant performance gain observed prove validity of the proposed approach and unveil a large potential of the assembled prototype.

Road dust should be considered as a secondary source of contamination in the environment, especially when re-suspended. In our study road dust samples were collected from 8 high-capacity urban roads in two districts of Kraków (Krowodrza and Nowa Huta). Total concentration of toxic elements, such as Cd, Cr, Cu, Mn, Zn, Co, Pb, Ni, Ba and Se were determined using ICP –MS ELAN 6100 Perkin Elmer. A fractionation study were performed using VI step sequential extraction, according to the modified method provided by Salomons and Fӧrstner. Appropriate quality control was ensured by using reagent blanks and analysing certified reference material BCR 723 and SRM 1848a. Concentration of metals in the road dust varied as follows [mg/kg]: Cd 1.02-1.78, Cr 34.4-90.3, Cu 65-224, Mn 232-760, Zn 261-365, Co 4.32-6.46, Pb 85.6-132, Ni 32.2-43.9, Ba 98.9-104 and Se 78.3-132. Degree of contamination of road dust from Nowa Huta was very high (Cdeg 54) and considerable for road dust from Krowodrza (Cdeg 25). Results revealed that road dust samples were heavily contaminated with Cd, Cu, Zn, Mn, Co, Pb, Ni, Ba and Se, in amounts exceeding multiple times geochemical background values. The chemical speciation study using VI step sequential extraction, followed by assessing risk assessment code (RAC) revealed that elements in road dust are mostly bound with mobile and easy bioavailable fractions such as carbonates and exchangeable cations, with the exception for Cr and Cu being mostly associated and fixed with residual and organic matter fraction.