49,057 research outputs found
On the Error Resilience of Ordered Binary Decision Diagrams
Ordered Binary Decision Diagrams (OBDDs) are a data structure that is used in
an increasing number of fields of Computer Science (e.g., logic synthesis,
program verification, data mining, bioinformatics, and data protection) for
representing and manipulating discrete structures and Boolean functions. The
purpose of this paper is to study the error resilience of OBDDs and to design a
resilient version of this data structure, i.e., a self-repairing OBDD. In
particular, we describe some strategies that make reduced ordered OBDDs
resilient to errors in the indexes, that are associated to the input variables,
or in the pointers (i.e., OBDD edges) of the nodes. These strategies exploit
the inherent redundancy of the data structure, as well as the redundancy
introduced by its efficient implementations. The solutions we propose allow the
exact restoring of the original OBDD and are suitable to be applied to
classical software packages for the manipulation of OBDDs currently in use.
Another result of the paper is the definition of a new canonical OBDD model,
called {\em Index-resilient Reduced OBDD}, which guarantees that a node with a
faulty index has a reconstruction cost , where is the number of nodes
with corrupted index
Sequential Circuit Design for Embedded Cryptographic Applications Resilient to Adversarial Faults
In the relatively young field of fault-tolerant cryptography, the main research effort has focused exclusively on the protection of the data path of cryptographic circuits. To date, however, we have not found any work that aims at protecting the control logic of these circuits against fault attacks, which thus remains the proverbial Achilles’ heel. Motivated by a hypothetical yet realistic fault analysis attack that, in principle, could be mounted against any modular exponentiation engine, even one with appropriate data path protection, we set out to close this remaining gap. In this paper, we present guidelines for the design of multifault-resilient sequential control logic based on standard Error-Detecting Codes (EDCs) with large minimum distance. We introduce a metric that measures the effectiveness of the error detection technique in terms of the effort the attacker has to make in relation to the area overhead spent in
implementing the EDC. Our comparison shows that the proposed EDC-based technique provides superior performance when compared against regular N-modular redundancy techniques. Furthermore, our technique scales well and does not affect the critical path delay
Complexity of term representations of finitary functions
The clone of term operations of an algebraic structure consists of all
operations that can be expressed by a term in the language of the structure. We
consider bounds for the length and the height of the terms expressing these
functions, and we show that these bounds are often robust against the change of
the basic operations of the structure
Estimating the Sizes of Binary Error-Correcting Constrained Codes
In this paper, we study binary constrained codes that are resilient to
bit-flip errors and erasures. In our first approach, we compute the sizes of
constrained subcodes of linear codes. Since there exist well-known linear codes
that achieve vanishing probabilities of error over the binary symmetric channel
(which causes bit-flip errors) and the binary erasure channel, constrained
subcodes of such linear codes are also resilient to random bit-flip errors and
erasures. We employ a simple identity from the Fourier analysis of Boolean
functions, which transforms the problem of counting constrained codewords of
linear codes to a question about the structure of the dual code. We illustrate
the utility of our method in providing explicit values or efficient algorithms
for our counting problem, by showing that the Fourier transform of the
indicator function of the constraint is computable, for different constraints.
Our second approach is to obtain good upper bounds, using an extension of
Delsarte's linear program (LP), on the largest sizes of constrained codes that
can correct a fixed number of combinatorial errors or erasures. We observe that
the numerical values of our LP-based upper bounds beat the generalized sphere
packing bounds of Fazeli, Vardy, and Yaakobi (2015).Comment: 51 pages, 2 figures, 9 tables, to be submitted to the IEEE Journal on
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