1,720,957 research outputs found
A PUF based on the non-linearity of memristors
No full textAs autonomous devices are increasingly used in security and safety-critical applications the security of the systems they comprise is of increasing concern. In such situations it is important that devices can be securely identified and trusted. When an IC or device is in the supply chain, or in the field, the lack of control over actors who can obtain physical access can compromise the trust and overall security of a system. Counterfeit chips may be incorporated into the device, compromising reliability or security. Additionally, for implemented devices, keys stored on-device may be copied by a bad actor. To help improve the security of such devices this paper proposes a new physical unclonable function (PUF) architecture, based on a TiOx memristor-based resistive memory (RRAM), that exploits the inherent analogue non-linearity in resistance of some memristor technologies. By directly exploiting non-linearity of memristor cells, rather than relying on the devices' absolute resistance at a single test voltage, a multi-bit-per-comparison PUF is created. As the architecture directly exploits cells' non-linearity, an additional source of hard-to-clone entropy is incorporated
A memristor fingerprinting and characterisation methodology for hardware security
No full textThe modern IC supply chain encompasses a large number of steps and manufacturers. In many applications it is critically important that chips are of the right quality and are assured to have been obtained from the legitimate supply chain. To this end, it is necessary to be able to uniquely identify systems to aid in supply chain tracking and quality assurance. Many identifiers, however, can be cloned onto counterfeit devices and are therefore untrustworthy. This paper proposes a methodology for using post-CMOS memristor devices as a fingerprint to uniquely identify ICs. To achieve this, memristors' unique and variable I-V characteristics are exploited to produce a fingerprint that can be generally applicable to a wide variety of different memristor technologies and identifiable over time, even where cell retention is non-ideal. In doing so it aims to minimise the hardware required on-chip both to minimise cost and maximise the auditability of the system. The methodology is applied to a TiOx memristor technology, and shown to be able to identify cells in a set
On the integration of physically unclonable functions into ARM TrustZone security technology
No full textAs Internet of Things (IoT) devices are increasingly used in industry and become further integrated into our daily lives the security of such devices is of paramount concern. Ensuring that the large amount of information that these devices collect is protected and only accessible to authenticated users is a critical requirement of the industry. One potentially inexpensive way to improve device security utilises a Physically Unclonable Function (PUF) to generate a unique random response per device. This random response can be generated in such a way that it can be regenerated reliably and repeatably allowing the response to be considered a signature for each device. This signature could then be used for authentication or key generation purposes, improving trust in IoT devices. The advantage of a PUF based system is that the response does not need to be stored in nonvolatile memory as it is regenerated on demand, hardening the system against physical attacks. With SoC FPGAs being inexpensive and widely available there is potential for their use in both industrial and consumer applications as an additional layer of hardware security. In this paper we investigate and implement a Trusted Execution Environment (TEE) based around a PUF solely implemented in the FPGA fabric on a Xilinx Zynq-7000 SoC FPGA. The PUF response is used to seed a generic entropy maximisation function or Pseudorandom Number Generator (PRNG) with a system controller capable of encrypting data to be useful only to the device. This system interacts with a software platform running in the ARM TrustZone on the ARM Cortex core in the SoC, which handles requests between user programs and the FPGA. The proposed PUF-based security module can generate unique random keys able to pass all NIST tests and protects against physical attacks on buses and nonvolatile memories. These improvements are achieved at a cost of fewer than half the resources on the Zynq-7000 SoC FPGA
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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