Pino Persiano

Constrained Bipartite Edge Coloring with Applications to Wavelength Routing

Motivated by the problem of efficient routing in all-optical networks, we study a constrained version of the bipartite edge coloring problem. We show that if the edges adjacent to a pair of opposite vertices of an L-regular bipartite graph are already colored with αL different colors, then the rest of the edges can be colored using at most (1+α/2)L colors. We also show that this bound is tight by constructing instances in which (1+α/2)L colors are indeed necessary. We also obtain tight bounds on the number of colors that each pair of opposite vertices can see.

A linear-time algorithm for the feasibility of pebble motion on trees

Abstract. We consider the following pebble motion problem. We are given a tree T with n vertices and two arrangements

A secure and private system for subscription-based remote services

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User privacy issues regarding certificates and the TLS protocol: the design and implementation of the SPSL protocol

and

An anonymous credential system and a privacy-aware PKI

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Sparse and limited wavelength conversion in all-optical tree networks

of k<n distinct pebbles numbered 1, . . ., k on distinct vertices of the tree. Pebbles can move along edges of T provided that at any given time at most one pebble is traveling along an edge and each vertex of T contains at most one pebble. We are asked the following question: Is arrangement

Edge coloring of bipartite graphs with constraints

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How to route and tax selfish unsplittable traffic

reachable from

Randomness-efficient non-interactive zero knowledge

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Optimal Pebble Motion on a Tree

? We present an algorithm that, on input two arrangements of k pebbles on a tree with n vertices, decides in time O(n) whether the two arrangements are reachable from one another. We also give an algorithm that, on input two reachable configurations, returns a sequence of moves that transforms one configuration into the other. The pebble motion problem on trees has various applications including memory management in distributed systems, robot motion planning, and deflection routing.