1,721,026 research outputs found
Design techniques for secure cryptographic circuits in deep submicron technologies
Full text linkOne of the main concerns of modern cryptographic devices is related to the possibility of stealing the secret information, which is processed or stored inside (e.g. personal data, PIN, passwords, payment details, ...). In the scientific community many efforts have been spent in the last decades, with the purpose to develop cryptographic algorithms, which are robust enough against any attempt to detect the cryptographic key of the algorithm itself. In the last years a new class of attacks, aimed at attacking one device at the physical level, gained even more importance. Their efficacy consists in the possibility to exploit the physical emissions of the device (e.g. power consumption, light, noise, electromagnetic radiation, ...), instead that trying to break the algorithm from a mathematical point of view. This class of attacks is known as Side Channel Attacks (SCAs) and their danger resides in the fact that they allow to steal the information leaking from the device, without leaving any trace of their activity, so that the victim of the attack (e.g. the owner of a smart card) could be completely unaware of them. Many countermeasures have been presented at each design level, in order to protect electronic circuits, which are the hardware basis of any cryptographic device, against them. In this work we focus on a particular class of SCAs: Power Analysis Attacks (PAAs). PAAs are able to find correlation between the power consumption of a digital circuit and the electrically internally processed data, exploiting the fact that with the reduction of the dimensions of the commercial electronic technologies this dependance becomes even more relevant. Therefore the new challenge of the semiconductor companies is to design and manufacture devices which are proven against this class of attacks, already from a hardware point of view, in order to provide the customer with reliable and optimized products.
The main contributions of this work are below summarized:
Present a new concept for the design of digital cryptographic circuits, whose purpose is to increase the level of securiy of crypto-devices against hardware attacks, in particulat against PAAs.
- Discuss the most known state-of-the-art security metrics and present a new methodology, as an improvement of the former ones, which should be considered in order to properly validate sub-micron cryptographic circuits.
- Design a new digital standard cell library, using a commercial sub-micron technology node, which has been characterized with extensive simulations using commercial EDA tools and has been evaluated using the most common security metrics.
- Define a new design flow, using the proposed standard cell library, which has been adopted for the design of a cryptographic test-chip; the design phases and the security evaluation of the test-chip are widely described and allow to prove the level of robustness of the new design style.
- Discuss a new class of Power Analysis Attacks, based on the leakage coming from the static power, which is becoming predominant in scaled sub-micron technologies, and prove through extensive simulations that the most known countermeasures against PAAs are not robust enough and therefore new metrics and design styles would be necessary
Activation of parasitic bipolar transistor during reverse recovery of MOSFET's intrinsic diode
No full textThe activation of the parasitic bipolar transistor during reverse recovery of the internal diode of a power MOSFET used as a fly-back diode in a half-bridge circuit topology is investigated. Experimental observations, obtained by means of a non-destructive tester, and 2D MEDICI simulations indicate that, among the various physical and geometrical parameters of MOSFET elementary cell, the resistance associated to the contact on the source region plays the most relevant role during the activation process
AN EXPERIMENTAL CLASSIFICATION OF DRAIN AND GATE CURRENT PULSES IN LOW-VOLTAGE POWER MOSFETS DURING RADIATION EXPOSURE
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
- …
