José Antonio Álvarez-Bermejo

DNA Sequencing Sensors: An Overview

The first sequencing of a complete genome was published forty years ago by the double Nobel Prize in Chemistry winner Frederick Sanger. That corresponded to the small sized genome of a bacteriophage, but since then there have been many complex organisms whose DNA have been sequenced. This was possible thanks to continuous advances in the fields of biochemistry and molecular genetics, but also in other areas such as nanotechnology and computing. Nowadays, sequencing sensors based on genetic material have little to do with those used by Sanger. The emergence of mass sequencing sensors, or new generation sequencing (NGS) meant a quantitative leap both in the volume of genetic material that was able to be sequenced in each trial, as well as in the time per run and its cost. One can envisage that incoming technologies, already known as fourth generation sequencing, will continue to cheapen the trials by increasing DNA reading lengths in each run. All of this would be impossible without sensors and detection systems becoming smaller and more precise. This article provides a comprehensive overview on sensors for DNA sequencing developed within the last 40 years.

Tetrazine-based chemistry for nitrite determination in a paper microfluidic device

We present a new chemistry to determine nitrites implemented in a microfluidic paper-based analytical device (µPAD). The device is fabricated in cellulose paper with a sample reception area and three replicate detection areas with recognition chemistry immobilized by adsorption. The method involves the use of nitrite in an acid medium reaction to generate nitrous acid, which produces the oxidation of s-dihydrotetrazine: 1,2-dihydro-3,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,2,4,5-tetrazine (DHBPTz), which change the detection zone from colorless to pink. We used a digital camera and smartphone for the quantitative analysis of nitrite with the color coordinate S of the HSV color space as the analytical parameter. Parameters such as concentration and volume of s-dihydrotetrazine, pH, sample volume and reaction time were studied. The detection limit for this method is 1.30µM nitrite. To estimate the selectivity of the method an interference study of common ions in water samples was performed. The procedure was applied to natural water and compared with reference procedures.

Managing key multicasting through orthogonal systems

Abstract In this paper we propose a new protocol for Group Key Management. The protocol is based on the use of orthogonal systems in vector spaces. The main advantage in comparison to other existing multicast key management protocols consists in small communications overheads, i.e. length and number of messages to be sent, as well as key storage, especially with respect to a comparable security level. This makes the protocol especially attractive when the number of legitimate receivers is large.

Hardware implementation of a new ECC key distribution protocol for securing Wireless Sensor Networks

Security in Wireless Sensor Networks (WSNs) is a major challenge for extending its applications. In this paper, a new protocol for key distribution in WSNs is proposed. The method, based on Elliptic Curve Cryptography, and named ECGDH-1, performs a double round key distribution, sharing a group key among the different nodes. For accelerating the scalar-point operations to be performed in each node, a hardware coprocessor with low power consumption, and 8-bit interface for sensor motes is proposed. The cryptographic processor, named ECCB163sens_bus8 allows completing a scalar-point multiplication in 240us operating at 8MHz, while consuming only 0.028mJ by operation when implemented in a Spartan 6 device.

A proposed asynchronous object load balancing method for parallel 3d image reconstruction applications

Scientific applications usually exhibit irregular patterns of execution and high resource usage Parallel architectures are a feasible solution to face these drawbacks, but porting software to parallel platforms means the addition of an extra layer of complexity to scientific software Abstractions such as Object Orientation and models like the concurrent object model may be of great help to develop scientific parallel applications The shared nature of parallel architectures and the stochastic condition of parallel schedulers underline the adaptivity as a desired feature for parallel applications Load Balancers are key for achieving adaptivity, and benefit from object oriented models in issues like load migration In this paper we present our experiences when porting scientific software using the concurrent object abstraction and a method to asynchronously invoke load balancers.

System to Detect Racial-Based Bullying through Gamification

Prevention and detection of bullying due to racial stigma was studied in school contexts using a system designed following “gamification” principles and integrating less usual elements, such as social interaction, augmented reality and cell phones in educational scenarios. “Grounded Theory” and “User Centered Design” were employed to explore coexistence inside and outside the classroom in terms of preferences and distrust in several areas of action and social frameworks of activity, and to direct the development of a cell phone app for early detection of school bullying scenarios. One hundred and fifty-one interviews were given at five schools selected for their high multiracial percentage and conflict. The most outstanding results were structural, that is the distribution of the classroom group by type of activity and subject being dealt with. Furthermore, in groups over 12 years of age, the relational structures in the classroom in the digital settings in which they participated with their cell phones did not reoccur, because face-to-face and virtual interaction between students with the supervision and involvement of the teacher combined to detect bullying caused by racial discrimination.

A scalable server for key distribution and its application to accounting

Media distribution over the Internet is a fact. Finding a way to protect content streaming is a hot topic. This paper presents both a new and efficient key multicasting protocol based on the use of orthogonal systems in vector spaces, and its scalable implementation by means of a platform independent server. The protocol outstands in exchanging a small number of tiny messages which helps the server to scale when facing a huge number of legitimate users.

Tracking Traitors in Web Services via Blind Signatures

This paper presents a method and its implementation proposal, built on the blind signatures protocol, to trace and report users sharing a valid license illegally when accessing services provided through Internet (Web services, Streaming, etc). The method devised is able to identify the legitimate user from those users who are illegally accessing services with a shared key. This method is robust when detecting licenses built with no authorization. An enhancement of the protocol to identify the last usage of a certain license is also provided, allowing to detect a traitor when an unauthorized copy of a license is used.

Elliptic Curve Cryptography hardware accelerator for high-performance secure servers

Security threats affecting electronics communications in the current world make necessary the encryption and authentication of every transaction. The increasing levels of security required are leading to an overload of transaction servers due to cryptographic tasks. In this paper, a hardware-implemented coprocessor for Elliptic Curve Cryptography operations is presented. This coprocessor enables the acceleration of secure services and can be implemented in the last generations FPGA, thus allowing to host in the same chip a software secure web/database server and the cryptographic coprocessor. Obtained results show advantages of the proposed solution when compared to software implementations and classical acceleration using graphics processing units. Moreover, the proposed cryptographic coprocessor presents improvements over other hardware implementations when area, performance and scalability are considered. The developed crypto-processor has been implemented in a xc7z020clg484-1 device from Xilinx, taking advantage of the synergy provided by the ARM microprocessors and the programmable logic for hardware implementations included in the device. This design requires only 9852 LUTs, while providing 8930 scalar-point operations per second when operating at 50 MHz, with a power consumption of 0.42 W.

Unified Compact ECC-AES Co-Processor with Group-Key Support for IoT Devices in Wireless Sensor Networks

Security is a critical challenge for the effective expansion of all new emerging applications in the Internet of Things paradigm. Therefore, it is necessary to define and implement different mechanisms for guaranteeing security and privacy of data interchanged within the multiple wireless sensor networks being part of the Internet of Things. However, in this context, low power and low area are required, limiting the resources available for security and thus hindering the implementation of adequate security protocols. Group keys can save resources and communications bandwidth, but should be combined with public key cryptography to be really secure. In this paper, a compact and unified co-processor for enabling Elliptic Curve Cryptography along to Advanced Encryption Standard with low area requirements and Group-Key support is presented. The designed co-processor allows securing wireless sensor networks with independence of the communications protocols used. With an area occupancy of only 2101 LUTs over Spartan 6 devices from Xilinx, it requires 15% less area while achieving near 490% better performance when compared to cryptoprocessors with similar features in the literature.