The oblivious transfer primitive is sufficient to implement secure multiparty computation. However, secure multiparty computation based on public-key cryptography is limited by the security and efficiency of the oblivious transfer implementation. We present a method to generate and distribute oblivious keys by exchanging qubits and by performing commitments using classical hash functions. With the presented hybrid approach of quantum and classical, we obtain a practical and high-speed oblivious transfer protocol. We analyse the security and efficiency features of the technique and conclude that it presents advantages in both areas when compared to public-key based techniques.

The aim of the study was to determine the sensory quality of the coffee cultivated in the Mantiqueira region of Brazil (Minas Gerais State) and to identify its main descriptors. The sensory quality of red and yellow coffee fruit varieties (Coffea arabica L.) grown in environments with different slopes, at altitudes ranging from 932 to 1,391 m, was analyzed in three different crop seasons. The dry processing method and the wet processing method, based on mechanical removal of skin and mucilage, were used. The variables were analyzed through correspondence analysis. There was no correspondence with sample discrimination between the direction the slope face and coffee sensory profile. The sensory characteristics of coffee such as flavor, acidity, body and sweetness correspond to the cultivation environment with altitudes above 1,050 m. However, for the red coffee fruit varieties, that correspondence only occurred when subjected to a wet‐processing method. The quality of the coffee as a micro‐region product was identified in this study at altitudes above 1,050 m. This effect was not found in natural red coffee fruit varieties. Practical Applications Environmental aspects such as latitude, longitude, altitude and slope, as well as different coffee varieties and processing methods were analyzed in consecutive crop seasons, based on multivariate logistic regression and correspondence analysis techniques. The impacts of different methods of coffee production and processing on beverage quality have been debated for years and will surely continue to be studied in the coming decades, mainly because it is a phenomenon of high complexity. The variations in the sensory profile of coffee produced in different countries or microregions, or even at different planting sites, are noteworthy.

It was possible to discriminate cv. Yellow Bourbon coffee samples, the sensory evaluations of which resulted in scores of ≥88 points, which are associated with growing environments at altitudes of ≥1200 m. © 2015 Society of Chemical Industry.

A quantum bit error rate (QBER) based algorithm for polarization random drift compensation is proposed. For a transmission window of 8 ms, for instance in aerial fiber installations, the algorithm overhead is below 1%. In an extreme turbulent situation, where the transmission window is as shorter as 0.8 ms, the overhead is still below 10%. Besides being able to operate smoothly, even in a very extreme situation, the algorithm overhead is also insensitive to the length of the communication system. It is upper layer protocol agnostic, and it is based on the mapping of the QBER on the Poincaré sphere. The algorithm finds the polarization reversal operator, which results in much lower overhead contrary to the blind methods currently used. The algorithm reverts the polarization random drift performing two QBER estimations and applying three rotations, at most. The uncertainty on the two QBER estimations defines an area over the sphere surface that is related with upper-layer protocols QBER threshold.