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Roberto Tamassia

  1. Oblivious Storage with Low I/O Overhead.

    Tue, 10/11/2011 - 15:01 — SomNambul
    Authors: Michael T. Goodrich, Roberto Tamassia, Michael Mitzenmacher, Olga Ohrimenko
    Subjects: Cryptography and Security
    Abstract

    We study oblivious storage (OS), a natural way to model privacy-preserving
    data outsourcing where a client, Alice, stores sensitive data at an
    honest-but-curious server, Bob. We show that Alice can hide both the content of
    her data and the pattern in which she accesses her data, with high probability,
    using a method that achieves O(1) amortized rounds of communication between her
    and Bob for each data access.

  2. Oblivious RAM Simulation with Efficient Worst-Case Access Overhead.

    Wed, 07/27/2011 - 15:01 — SomNambul
    Authors: Michael T. Goodrich, Roberto Tamassia, Michael Mitzenmacher, Olga Ohrimenko
    Subjects: Cryptography and Security
    Abstract

    Oblivious RAM simulation is a method for achieving confidentiality and
    privacy in cloud computing environments. It involves obscuring the access
    patterns to a remote storage so that the manager of that storage cannot infer
    information about its contents. Existing solutions typically involve small
    amortized overheads for achieving this goal, but nevertheless involve
    potentially huge variations in access times, depending on when they occur. In
    this paper, we show how to de-amortize oblivious RAM simulations, so that each
    access takes a worst-case bounded amount of time.

  3. Privacy-Preserving Data-Oblivious Geometric Algorithms for Geographic Data.

    Mon, 09/13/2010 - 15:01 — SomNambul
    Authors: Michael T. Goodrich, Roberto Tamassia, David Eppstein
    Subjects: Computational Geometry
    Abstract

    We give efficient data-oblivious algorithms for several fundamental geometric
    problems that are relevant to geographic information systems, including planar
    convex hulls and all-nearest neighbors. Our methods are "data-oblivious" in
    that they don't perform any data-dependent operations, with the exception of
    operations performed inside low-level blackbox circuits having a constant
    number of inputs and outputs.

  4. Efficient Authenticated Data Structures for Graph Connectivity and Geometric Search Problems.

    Mon, 08/31/2009 - 17:16 — SomNambul
    Authors: Michael T. Goodrich, Roberto Tamassia, Nikos Triandopoulos
    Subjects: Cryptography and Security
    Abstract

    Authenticated data structures provide cryptographic proofs that their answers
    are as accurate as the author intended, even if the data structure is being
    controlled by a remote untrusted host. We present efficient techniques for
    authenticating data structures that represent graphs and collections of
    geometric objects. We introduce the path hash accumulator, a new primitive
    based on cryptographic hashing for efficiently authenticating various
    properties of structured data represented as paths, including any decomposable
    query over sequences of elements.

Math-arch

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