Sciweavers

CSR
2008
Springer
14 years 1 months ago
Comparing Universal Covers in Polynomial Time
The universal cover TG of a connected graph G is the unique (possible infinite) tree covering G, i.e., that allows a locally bijective homomorphism from TG to G. Universal covers h...
Jirí Fiala, Daniël Paulusma
CSR
2008
Springer
14 years 1 months ago
Cryptanalysis of Stickel's Key Exchange Scheme
We offer cryptanalysis of a key exchange scheme due to Stickel [11], which was inspired by the well-known Diffie-Hellman protocol. We show that Stickel's choice of platform (t...
Vladimir Shpilrain
CSR
2008
Springer
14 years 1 months ago
A Semantic Proof of Polytime Soundness of Light Affine Logic
We define a denotational semantics for Light Affine Logic (LAL) which has the property that denotations of functions are polynomial time computable by construction of the model. Th...
Ugo Dal Lago, Martin Hofmann
CSR
2008
Springer
14 years 1 months ago
Synchronization of Grammars
Abstract. Deterministic graph grammars are finite devices which generate the transition graphs of pushdown automata. We define the notion of synchronization by grammars, generalizi...
Didier Caucal, Stéphane Hassen
CSR
2008
Springer
14 years 1 months ago
Public Key Encryption and Encryption Emulation Attacks
The main purpose of this paper is to show that public key encryption can be secure against the "encryption emulation" attack (on the sender's encryption) by computat...
Denis Osin, Vladimir Shpilrain
CSR
2008
Springer
14 years 1 months ago
Additive Preconditioning for Matrix Computations
Versus the customary preconditioners, our weakly random ones are generated more readily and for a much larger class of input matrices. Furthermore our preconditioners have a wider...
Victor Y. Pan, Dmitriy Ivolgin, Brian Murphy, Rhys...
CSR
2008
Springer
14 years 1 months ago
On the Complexity of Membership and Counting in Height-Deterministic Pushdown Automata
Abstract. While visibly pushdown languages properly generalise regular languages and are properly contained in deterministic context-free languages, the complexity of their members...
Nutan Limaye, Meena Mahajan, Antoine Meyer
CSR
2008
Springer
14 years 1 months ago
Invariant Generation for P-Solvable Loops with Assignments
We discuss interesting properties of a general technique for inferring polynomial invariants for a subfamily of imperative loops, called the P-solvable loops, with assignments only...
Laura Kovács
CSR
2008
Springer
14 years 1 months ago
Logic and Rational Languages of Words Indexed by Linear Orderings
We prove that every rational language of words indexed by linear orderings is definable in monadic second-order logic. We also show that the converse is true for the class of langu...
Nicolas Bedon, Alexis Bès, Olivier Carton, ...