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Abstract-In this paper, a novel high speed ECC processor implementation for point multiplication on Field Programmable Gate Array (FPGA) is proposed. A new segmented pipelined fullprecision multiplier is used to reduce the latency and the LopezDahab (LD) Montgomery point multiplication algorithm is modified for careful scheduling to avoid data dependency resulting in a drastic reduction in the number of clock cycles required. The proposed ECC architecture has been implemented on Xilinx FPGAs Virtex4, Virtex5 and Virtex7 families. To our knowledge, our single multiplier and three multipliers based designs show the fastest performance to date when compared to reported works individually. Our one multiplier based ECC processor also achieves the highest reported speed together with the best reported area-time performance on Virtex4 (5.32 µs at 210 MHz), on Virtex5 (4.91 µs at 228 MHz), and on the more advanced Virtex7, (3.18 µs at 352 MHz). Finally, the proposed three multiplier based ECC implementation is the first work reporting the lowest number of clock cycles and the fastest ECC processor design on FPGA (450 clock cycles to get 2.83 µs on Virtex7).

Chitosan was chemically modified to produce quaternary ammonium salts in order to improve its antimicrobial activity and physicochemical properties. Quaternization of N-alkyl chitosan derivatives was carried out using alkyl iodide to elaborate water-soluble cationic polyelectrolytes ( N, N, N-trimethylchitosan, TMC). TMC was characterized by (1)H NMR spectroscopy; the quaternization degree was determined from (1)H NMR spectra and by titration of iodide ion. The antibacterial activity of hydroxypropylcellulose (HPC) films or coatings associated with chitosan or TMC as biocide was evaluated against the growth of Listeria monocytogenes and Salmonella typhimurium. The HPC-chitosan and HPC-TMC coatings exhibited a total inhibition on solid medium of both bacterial strains. Experiments conducted in liquid medium showed that the inhibitory activity against the growth of Listeria innocua was improved after chemical modification. Moreover, physicochemical properties of films were evaluated to determine their potential for food applications. The addition of the antibacterial agents showed a significant impact on the moisture barrier and mechanical properties of HPC films.

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Abstract. Two new FPGA designs for the Advanced Encryption Standard (AES) are presented. The first is believed to be the fastest, achieving 25 Gbps throughput using a Xilinx Spartan-III (XC3S2000) device. The second is believed to be the smallest and fits into a Xilinx Spartan-II (XC2S15) device, only requiring two block memories and 124 slices to achieve a throughput of 2.2 Mbps. These designs show the extremes of what is possible and have radically different applications from high performance e-commerce IPsec servers to low power mobile and home applications. The high speed design presented here includes support for continued throughput during key changes for both encryption and decryption which previous pipelined designs have omitted.