899,999 research outputs found
Power analysis on smartcard algorithms using simulation
This paper presents the results from a power analysis of the AES and RSA algorithms by\ud
simulation using the PINPAS tool. The PINPAS tool is capable of simulating the power\ud
consumption of assembler programs implemented in, amongst others, Hitachi H8/300\ud
assembler. The Hitachi H8/300 is a popular CPU for smartcards. Using the PINPAS tool, the\ud
vulnerability for power analysis attacks of straightforward AES and RSA implementations is\ud
examined. In case a vulnerability is found countermeasures are added to the implementation\ud
that attempt to counter power analysis attacks. After these modifications the analysis is\ud
performed again and the new results are compared to the original results
Symbolic Abstractions for Quantum Protocol Verification
Quantum protocols such as the BB84 Quantum Key Distribution protocol exchange
qubits to achieve information-theoretic security guarantees. Many variants
thereof were proposed, some of them being already deployed. Existing security
proofs in that field are mostly tedious, error-prone pen-and-paper proofs of
the core protocol only that rarely account for other crucial components such as
authentication. This calls for formal and automated verification techniques
that exhaustively explore all possible intruder behaviors and that scale well.
The symbolic approach offers rigorous, mathematical frameworks and automated
tools to analyze security protocols. Based on well-designed abstractions, it
has allowed for large-scale formal analyses of real-life protocols such as TLS
1.3 and mobile telephony protocols. Hence a natural question is: Can we use
this successful line of work to analyze quantum protocols? This paper proposes
a first positive answer and motivates further research on this unexplored path
Exploiting timing information in event-triggered stabilization of linear systems with disturbances
In the same way that subsequent pauses in spoken language are used to convey
information, it is also possible to transmit information in communication
networks not only by message content, but also with its timing. This paper
presents an event-triggering strategy that utilizes timing information by
transmitting in a state-dependent fashion. We consider the stabilization of a
continuous-time, time-invariant, linear plant over a digital communication
channel with bounded delay and subject to bounded plant disturbances and
establish two main results. On the one hand, we design an encoding-decoding
scheme that guarantees a sufficient information transmission rate for
stabilization. On the other hand, we determine a lower bound on the information
transmission rate necessary for stabilization by any control policy
CSR5: An Efficient Storage Format for Cross-Platform Sparse Matrix-Vector Multiplication
Sparse matrix-vector multiplication (SpMV) is a fundamental building block
for numerous applications. In this paper, we propose CSR5 (Compressed Sparse
Row 5), a new storage format, which offers high-throughput SpMV on various
platforms including CPUs, GPUs and Xeon Phi. First, the CSR5 format is
insensitive to the sparsity structure of the input matrix. Thus the single
format can support an SpMV algorithm that is efficient both for regular
matrices and for irregular matrices. Furthermore, we show that the overhead of
the format conversion from the CSR to the CSR5 can be as low as the cost of a
few SpMV operations. We compare the CSR5-based SpMV algorithm with 11
state-of-the-art formats and algorithms on four mainstream processors using 14
regular and 10 irregular matrices as a benchmark suite. For the 14 regular
matrices in the suite, we achieve comparable or better performance over the
previous work. For the 10 irregular matrices, the CSR5 obtains average
performance improvement of 17.6\%, 28.5\%, 173.0\% and 293.3\% (up to 213.3\%,
153.6\%, 405.1\% and 943.3\%) over the best existing work on dual-socket Intel
CPUs, an nVidia GPU, an AMD GPU and an Intel Xeon Phi, respectively. For
real-world applications such as a solver with only tens of iterations, the CSR5
format can be more practical because of its low-overhead for format conversion.
The source code of this work is downloadable at
https://github.com/bhSPARSE/Benchmark_SpMV_using_CSR5Comment: 12 pages, 10 figures, In Proceedings of the 29th ACM International
Conference on Supercomputing (ICS '15
Simulating Quantum Correlations with Finite Communication
Assume Alice and Bob share some bipartite -dimensional quantum state. A
well-known result in quantum mechanics says that by performing two-outcome
measurements, Alice and Bob can produce correlations that cannot be obtained
locally, i.e., with shared randomness alone. We show that by using only two
bits of communication, Alice and Bob can classically simulate any such
correlations. All previous protocols for exact simulation required the
communication to grow to infinity with the dimension . Our protocol and
analysis are based on a power series method, resembling Krivine's bound on
Grothendieck's constant, and on the computation of volumes of spherical
tetrahedra.Comment: 19 pages, 3 figures, preliminary version in IEEE FOCS 2007; to appear
in SICOM
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