scholarly journals Pragmatism vs. Elegance: Comparing Two Approaches to Simple Power Attacks on AES

Author(s):  
Valentina Banciu ◽  
Elisabeth Oswald
Keyword(s):  
Author(s):  
Shayan Moini ◽  
Xiang Li ◽  
Peter Stanwicks ◽  
George Provelengios ◽  
Wayne Burleson ◽  
...  

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Haim Kalman

AbstractAny scientific behavior is best represented by nondimensional numbers. However, in many cases, for pneumatic conveying systems, dimensional equations are developed and used. In some cases, many of the nondimensional equations include Reynolds (Re) and Froude (Fr) numbers; they are usually defined for a limited range of materials and operating conditions. This study demonstrates that most of the relevant flow types, whether in horizontal or vertical pipes, can be better described by Re and Archimedes (Ar) numbers. Ar can also be used in hydraulic conveying systems. This paper presents many threshold velocities that are accurately defined by Re as a simple power function of Ar. Many particulate materials are considered by Ar, thereby linking them to a common behavior. Using various threshold velocities, a flow regime chart for horizontal conveying is presented in this paper.


Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 219
Author(s):  
Elena Fedorova ◽  
B.I. Hnatyk ◽  
V.I. Zhdanov ◽  
A. Del Popolo

3C111 is BLRG with signatures of both FSRQ and Sy1 in X-ray spectrum. The significant X-ray observational dataset was collected for it by INTEGRAL, XMM-Newton, SWIFT, Suzaku and others. The overall X-ray spectrum of 3C 111 shows signs of a peculiarity with the large value of the high-energy cut-off typical rather for RQ AGN, probably due to the jet contamination. Separating the jet counterpart in the X-ray spectrum of 3C 111 from the primary nuclear counterpart can answer the question is this nucleus truly peculiar or this is a fake “peculiarity” due to a significant jet contribution. In view of this question, our aim is to estimate separately the accretion disk/corona and non-thermal jet emission in the 3C 111 X-ray spectra within different observational periods. To separate the disk/corona and jet contributions in total continuum, we use the idea that radio and X-ray spectra of jet emission can be described by a simple power-law model with the same photon index. This additional information allows us to derive rather accurate values of these contributions. In order to test these results, we also consider relations between the nuclear continuum and the line emission.


2009 ◽  
Vol 18 (09) ◽  
pp. 1395-1411 ◽  
Author(s):  
LEONARDO CAMPANELLI

We analyze the generation of seed magnetic fields during de Sitter inflation considering a noninvariant conformal term in the electromagnetic Lagrangian of the form [Formula: see text], where I(ϕ) is a pseudoscalar function of a nontrivial background field ϕ. In particular, we consider a toy model that could be realized owing to the coupling between the photon and either a (tachyonic) massive pseudoscalar field or a massless pseudoscalar field nonminimally coupled to gravity, where I follows a simple power law behavior I(k,η) = g/(-kη)β during inflation, while it is negligibly small subsequently. Here, g is a positive dimensionless constant, k the wave number, η the conformal time, and β a real positive number. We find that only when β = 1 and 0.1 ≲ g ≲ 2 can astrophysically interesting fields be produced as excitation of the vacuum, and that they are maximally helical.


2016 ◽  
Vol 67 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Tomáš Fabšič ◽  
Ondrej Gallo ◽  
Viliam Hromada

Abstract It is known that a naive implementation of the decryption algorithm in the McEliece cryptosystem allows an attacker to recover the secret matrix P by measuring the power consumption. We demonstrate that a similar threat is present in the QC-LDPC variant of the McEliece cryptosystem. We consider a naive implementation of the decryption algorithm in the QC-LDPC McEliece cryptosystem. We demonstrate that this implementation leaks information about positions of ones in the secret matrix Q. We argue that this leakage allows an attacker to completely recover the matrix Q. In addition, we note that the quasi-cyclic nature of the matrix Q allows to accelerate the attack significantly.


2013 ◽  
Vol 10 (5) ◽  
pp. 114-119 ◽  
Author(s):  
Chen Aidong ◽  
Xu Sen ◽  
Chen Yun ◽  
Qin Zhiguang
Keyword(s):  

Author(s):  
Thorben Moos ◽  
Amir Moradi

In recent years it has been demonstrated convincingly that the standby power of a CMOS chip reveals information about the internally stored and processed data. Thus, for adversaries who seek to extract secrets from cryptographic devices via side-channel analysis, the static power has become an attractive quantity to obtain. Most works have focused on the destructive side of this subject by demonstrating attacks. In this work, we examine potential solutions to protect circuits from silently leaking sensitive information during idle times. We focus on countermeasures that can be implemented using any common digital standard cell library and do not consider solutions that require full-custom or analog design flow. In particular, we evaluate and compare a set of five distinct standard-cell-based hiding countermeasures, including both, randomization and equalization techniques. We then combine the hiding countermeasures with state-of-the-art hardware masking in order to amplify the noise level and achieve a high resistance against attacks. An important part of our contribution is the proposal and evaluation of the first ever standard-cell-based balancing scheme which achieves perfect data-independence on paper, i.e., in absence of intra-die process variations and aging effects. We call our new countermeasure Exhaustive Logic Balancing (ELB). While this scheme, applied to a threshold implementation, provides the highest level of resistance in our experiments, it may not be the most cost effective option due to the significant resource overhead associated. All evaluated countermeasures and combinations thereof are applied to a serialized hardware implementation of the PRESENT block cipher and realized as cryptographic co-processors on a 28nm CMOS ASIC prototype. Our experimental results are obtained through real-silicon measurements of a fabricated die of the ASIC in a temperature-controlled environment using a source measure unit (SMU). We believe that our elaborate comparison serves as a useful guideline for hardware designers to find a proper tradeoff between security and cost for almost any application.


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