118,365 research outputs found
Il ruolo determinante del consulente tecnico ingegnere per il successo delle operazioni in project financing
No full textIl consulente tecnico ingegnere nelle operazioni di project financing - Le opportunità concesse dal D. Lgs. 18 aprile 2016, n. 50
No full textQualità ambientale nei musei e negli archivi: un metodo di analisi e valutazione dei dati fisici ambientali
No full textLa distruzione dell'oggettività morale: l'emotivismo etico di Alfred J. Ayer e Charles L. Stevenson
No full textIl problema dell'oggettività dei giudizi morali nell'emotivismo etico dal Circolo di Vienna a Charles L. Stevenson
Design techniques for secure cryptographic circuits in deep submicron technologies
No full textOne 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
Properties of the electron-hole plasma in GaAs-(Ga,Al)As quantum wells: The influence of the finite well width
No full textPhotoluminescence spectra of the electron-hole plasma confined in GaAs-(Ga,Al)As quantum wells are presented. The spectra have been successfully fitted using a single-plasmon pole approximation. The results clearly show that the band-gap reduction Eg(w) depends on the width w of the well and is smaller than in a strictly two-dimensional plasma. Further, theoretical estimations of Eg(w) are in good agreement with our experimental results
Canine epithelial skin tumours: Expression of the stem cell markers Lgr5, Lgr6 and Sox9 in light of new cancer stem cell theories
No full textEvidence is accumulating that tumour development is driven by cancer stem cells (CSCs). In order to understand the presence and potential contribution of stem cells (SCs) as tumour-initiating cells in canine cutaneous tumours, we selected three putative SC markers (Lgr5, Lgr6 and Sox9) and investigated their expression pattern, level of protein and mRNA expression, in 43 canine hair follicle (HF) and 18 canine cutaneous epidermal tumours by immunohistochemistry and qRT-PCR, using normal skin samples as controls. Lgr5 protein expression was not detected in epidermal and HF tumours; however, Lgr5 mRNA overexpression was evident in some HF tumours. Sox9 was expressed in several tumour cases, both at the protein and mRNA level. The Lgr6 antibody tested was not suitable for formalin-fixed paraffin-embedded tissue samples, but Lgr6 gene showed higher expression in several samples of both HF and epidermal tumours compared with normal skin. Significantly higher mRNA expression levels of the three SC markers were found in trichoblastomas (TB) compared with basal cell carcinomas (BCC). The present results indicated that canine HF and epidermal tumours might have common tumour-initiating cells. The mRNA expression of the three selected SC markers, especially Lgr5, could be potentially useful in the distinction between canine TB and BCC
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