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Author

Encarnación Castillo

Other affiliations: Florida State University
Bio: Encarnación Castillo is an academic researcher from University of Granada. The author has contributed to research in topics: Digital signature & Digital watermarking. The author has an hindex of 13, co-authored 72 publications receiving 689 citations. Previous affiliations of Encarnación Castillo include Florida State University.


Papers
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Journal ArticleDOI
TL;DR: A procedure for intellectual property protection of digital circuits called IPP@HDL is presented, which relies on hosting the bits of the digital signature within memory structures or combinational logic that are part of the system at the high level description of the design.
Abstract: In this paper, a procedure for intellectual property protection (IPP) of digital circuits called IPP@HDL is presented. Its aim is to protect the author rights in the development and distribution of reusable modules by means of an electronic signature. The technique relies on hosting the bits of the digital signature within memory structures or combinational logic that are part of the system, at the high level description of the design. Thus, the area of the system is not increased and the signature is difficult to change or to remove without damaging the design. The technique also includes a procedure for secure signature extraction requiring minimal modifications to the system and without interfering its normal operation. The benefits of the presented procedure are illustrated with programmable logic and cell-based application-specific integrated circuit examples with several signature lengths. These design examples show no performance degradation and a negligible area increase, while probabilistic analyses show that the proposed IPP scheme offers high resistance against attacks.

123 citations

Proceedings ArticleDOI
24 Mar 2010
TL;DR: In this article, a non-linear effect in the frequency-temperature response has been detected, and the sensibility of frequency with respect to voltage variations is greater than the measured in previous works.
Abstract: In this paper, some experiments about thermal sensors based on ring-oscillator in low-voltage Virtex series FPGAs are presented. A non linear effect in the frequency-temperature response has been detected, and the sensibility of frequency with respect to voltage variations is greater than the measured in previous works. A quadratic polynomial function fits better the sensor response, and an increment in the number of inverters in the oscillator is effective to reduce the voltage sensibility.

57 citations

Journal ArticleDOI
TL;DR: This novel method is divided in two stages: the first step consists on a one-step wavelet-based preprocessing for simultaneous baseline and high-frequency noise suppression, while the second stage efficiently detects fetal QRS complexes allowing FHR monitoring.

57 citations

Journal ArticleDOI
TL;DR: This paper illustrates the application of the discrete wavelet transform (DWT) for wandering and noise suppression in electrocardiographic (ECG) signals with a novel one-step implementation, which allows improving the overall denoising process.
Abstract: This paper illustrates the application of the discrete wavelet transform (DWT) for wandering and noise suppression in electrocardiographic (ECG) signals. A novel one-step implementation is presented, which allows improving the overall denoising process. In addition an exhaustive study is carried out, defining threshold limits and thresholding rules for optimal wavelet denoising using this presented technique. The system has been tested using synthetic ECG signals, which allow accurately measuring the effect of the proposed processing. Moreover, results from real abdominal ECG signals acquired from pregnant women are presented in order to validate the presented approach.

48 citations

Journal ArticleDOI
TL;DR: The pairing of FPAA and FPGA devices conforms a compact and versatile bio-signal acquisition platform and has shown very good performance with different types of electrodes, and has also demonstrated the dynamic reconfiguration capabilities of these devices.
Abstract: This paper presents an electrocardiogram (ECG) acquisition system based on reconfigurable devices. This system allows redesigning the analog conditioning stage thanks to the use of a Field Programmable Analog Array (FPAA) device, which may be adapted to the requirements of the signal shape and/or medical specifications. Simulated and real ECG signals have been acquired using this system in a three-lead configuration. A detailed study of its technical features has been carried out, showing good suitability for ECG acquisition. Further digital ECG signal processing is performed on a Field Programmable Gate Array (FPGA) device, which has allowed different digital configurations to be tested, including FIR and wavelet filtering and identification of wave features such as the QRS complex. In addition, the FPGA device is in charge of FPAA reconfiguration. Thus, the pairing of FPAA and FPGA devices conforms a compact and versatile bio-signal acquisition platform. This platform has shown very good performance with different types of electrodes, and has also demonstrated the dynamic reconfiguration capabilities of these devices, which enable, for example, the tuning of gain and bandwidth as required by different input conditions and ECG application requirements. The analyzed performance parameters provide values such as 102 dB CMRR (Common-Mode Rejection Ratio), 14-bit ADC resolution, and 75 dB SNR (signal-to-noise ratio), among others, thus satisfying the minimum requirements for clinical use.

45 citations


Cited by
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01 Apr 1997
TL;DR: The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity.
Abstract: The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

2,188 citations

Journal ArticleDOI
TL;DR: The authors suggest that with the potential of these nanomaterials in sensing more research is needed on understanding their optical properties and why the synthetic methods influence their properties so much, into methods of surface functionalization that provide greater selectivity in sensing and into new sensing concepts that utilise the virtues of these nano-materials.
Abstract: Carbon and graphene quantum dots (CQDs and GQDs), known as zero-dimensional (0D) nanomaterials, have been attracting increasing attention in sensing and bioimaging. Their unique electronic, fluores...

570 citations

Journal ArticleDOI
TL;DR: Simulation results for a set of ISCAS-89 benchmark circuits and the advanced-encryption-standard IP core show that high levels of security can be achieved at less than 5% area and power overhead under delay constraint.
Abstract: Hardware intellectual-property (IP) cores have emerged as an integral part of modern system-on-chip (SoC) designs. However, IP vendors are facing major challenges to protect hardware IPs from IP piracy. This paper proposes a novel design methodology for hardware IP protection using netlist-level obfuscation. The proposed methodology can be integrated in the SoC design and manufacturing flow to simultaneously obfuscate and authenticate the design. Simulation results for a set of ISCAS-89 benchmark circuits and the advanced-encryption-standard IP core show that high levels of security can be achieved at less than 5% area and power overhead under delay constraint.

468 citations

Journal ArticleDOI
15 Jul 2014
TL;DR: This tutorial will provide a review of some of the existing counterfeit detection and avoidance methods, and discuss the challenges ahead for implementing these methods, as well as the development of new Detection and avoidance mechanisms.
Abstract: As the electronic component supply chain grows more complex due to globalization, with parts coming from a diverse set of suppliers, counterfeit electronics have become a major challenge that calls for immediate solutions. Currently, there are a few standards and programs available that address the testing for such counterfeit parts. However, not enough research has yet addressed the detection and avoidance of all counterfeit partsVrecycled, remarked, overproduced, cloned, out-of-spec/defective, and forged documentationVcurrently infiltrating the electronic component supply chain. Even if they work initially, all these parts may have reduced lifetime and pose reliability risks. In this tutorial, we will provide a review of some of the existing counterfeit detection and avoidance methods. We will also discuss the challenges ahead for im- plementing these methods, as well as the development of new detection and avoidance mechanisms.

424 citations

Journal ArticleDOI
TL;DR: Carbon quantum dots as discussed by the authors are a type of spherical or sphere-like nanoparticles of less than 10 nm in size and have been subsequently named as carbon quantum dots or carbon nanodots.
Abstract: Small carbon nanoparticles are an emerging member of the carbonaceous nanomaterial family and have been subsequently named as “carbon quantum dots” or “carbon nanodots”. Generally, carbon quantum dots are a type of spherical or sphere-like nanoparticles of less than 10 nm in size. Due to their unique properties, for example, size-dependent fluorescence, non-toxicity, biocompatibility, and easy accessibility, carbon quantum dots possess a great many potential applications in a range of fields from chemical sensing and imaging to catalysis and drug delivery, and thus are appealing to a number of researchers in nanoscience and nanotechnology. In this review, we give a brief introduction of the synthesis and fundamental properties of carbon quantum dots, then present their applications in metal ion sensing in detail along with illustrating the related mechanisms, and finally come up with some challenges currently faced and future outlooks for this fascinating carbon material. We hope this review could be helpful for readers who are preparing to join and/or have joined the research field of carbon quantum dots.

386 citations