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We consider the problem of efficiently proving the integrity of data stored at untrusted servers. In the provable data possession (PDP) model, the client preprocesses the data and then sends it to an untrusted server for storage, while keeping a small amount of meta-data. The client later asks the server to prove that the stored data has not been tampered(More)
We present a collection of new techniques for designing and analyzing eecient external-memory algorithms for graph problems and illustrate how these techniques can be applied to a wide variety of speciic problems. Our results include: Proximate-neighboring. We present a simple method for deriving external-memory lower bounds via reductions from a problem we(More)
A directed graph is upward planar if it can be drawn in the plane such that every edge is a monotonically increasing curve in the vertical direction, and no two edges cross. An undirected graph is recti-linear planar if it can be drawn in the plane such that every edge is a horizontal or vertical segment, and no two edges cross. Testing upward planarity and(More)
We study the problem of providing privacy-preserving access to an outsourced honest-but-curious data repository for a group of trusted users. We show that such privacy-preserving data access is possible using a combination of probabilistic encryp-tion, which directly hides data values, and stateless oblivious RAM simulation, which hides the pattern of data(More)
We study a general version of the multicast authentication problem where the underlying network, controlled by an adversary, may drop chosen packets, rearrange the order of the packets in an arbitrary way, and inject new packets into the transmitted stream. Prior work on the problem has focused on less general models, where random, rather than(More)
This paper considers the problem of verifying the correctness of geometric structures. In particular, we design optimal checkers for convex polytopes in two and higher dimensions, and for various types of planar subdivisions, such as triangulations, Delaunay triangulations, and convex subdivisions. Our checkers are simpler and more general than the ones(More)
Several data presentation problems involve drawing graphs so that they are easy to read and understand. Examples include circuit schematics and software engineering diagrams. In this paper we present a bibliographic survey on algorithms whose goal is to produce aesthetically pleasing drawings of graphs. Research on this topic is spread over the broad(More)