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Ronald Cramer - One of the best experts on this subject based on the ideXlab platform.

  • optimal Algebraic Manipulation detection codes in the constant error model
    Theory of Cryptography Conference, 2015
    Co-Authors: Ronald Cramer, Carles Padro, Chaoping Xing
    Abstract:

    Algebraic Manipulation detection (AMD) codes, introduced at EUROCRYPT 2008, may, in some sense, be viewed as keyless combinatorial authentication codes that provide security in the presence of an oblivious, Algebraic attacker. Its original applications included robust fuzzy extractors, secure message transmission and robust secret sharing. In recent years, however, a rather diverse array of additional applications in cryptography has emerged. In this paper we consider, for the first time, the regime of arbitrary positive constant error probability e in combination with unbounded cardinality M of the message space. There are several applications where this model makes sense. Adapting a known bound to this regime, it follows that the binary length ρ of the tag satisfies ρ ≥ loglogM + Ω e (1). In this paper, we shall call AMD codes meeting this lower bound optimal. Known constructions, notably a construction based on dedicated polynomial evaluation codes, are a multiplicative factor 2 off from being optimal. By a generic enhancement using error-correcting codes, these parameters can be further improved but remain suboptimal. Reaching optimality efficiently turns out to be surprisingly nontrivial. We propose a novel constructive method based on symmetries of codes. This leads to an explicit construction based on certain BCH codes that improves the parameters of the polynomial construction and to an efficient randomized construction of optimal AMD codes based on certain quasi-cyclic codes. In all our results, the error probability e can be chosen as an arbitrarily small positive real number.

  • optimal Algebraic Manipulation detection codes in the constant error model
    2014
    Co-Authors: Ronald Cramer, Carles Padro, Chaoping Xing
    Abstract:

    Algebraic Manipulation detection (AMD) codes, introduced at EUROCRYPT 2008, may, in some sense, be viewed as keyless combinatorial authentication codes that provide security in the presence of an oblivious, Algebraic attacker. Its original applications included robust fuzzy extractors, secure message transmission and robust secret sharing. In recent years, however, a rather diverse array of additional applications in cryptography has emerged. In this paper we consider, for the first time, the regime of arbitrary positive constant error probability e in combination with unbounded cardinality M of the message space. There are several applications where this model makes sense. Adapting a known bound to this regime, it follows that the binary length ρ of the tag satisfies ρ ≥ log logM +Ωe(1). In this paper, we shall call AMD codes meeting this lower bound optimal. Known constructions, notably a construction based on dedicated polynomial evaluation codes, are a multiplicative factor 2 off from being optimal. By a generic enhancement using error-correcting codes, these parameters can be further improved but remain suboptimal. Reaching optimality efficiently turns out to be surprisingly nontrivial. Owing to our refinement of the mathematical perspective on AMD codes, which focuses on symmetries of codes, we propose novel constructive principles. This leads to an explicit construction based on certain BCH codes that improves the parameters of the polynomial construction and to an efficient randomized construction of optimal AMD codes based on certain quasi-cyclic codes. In all our results, the error probability e can be chosen as an arbitrarily small positive real number.

  • detection of Algebraic Manipulation with applications to robust secret sharing and fuzzy extractors
    International Cryptology Conference, 2008
    Co-Authors: Ronald Cramer, Carles Padro, Yevgeniy Dodis, Serge Fehr, Daniel Wichs
    Abstract:

    Consider an abstract storage device Σ(G) that can hold a single element x from a fixed, publicly known finite group G. Storage is private in the sense that an adversary does not have read access to Σ(G) at all. However, Σ(G) is non-robust in the sense that the adversary can modify its contents by adding some offset Δ ∈ G. Due to the privacy of the storage device, the value Δ can only depend on an adversary's a priori knowledge of x. We introduce a new primitive called an Algebraic Manipulation detection (AMD) code, which encodes a source s into a value x stored on Σ(G) so that any tampering by an adversary will be detected. We give a nearly optimal construction of AMD codes, which can flexibly accommodate arbitrary choices for the length of the source s and security level. We use this construction in two applications: - We show how to efficiently convert any linear secret sharing scheme into a robust secret sharing scheme, which ensures that no unqualified subset of players can modify their shares and cause the reconstruction of some value s′ ≠ s. - We show how to build nearly optimal robust fuzzy extractors for several natural metrics. Robust fuzzy extractors enable one to reliably extract and later recover random keys from noisy and non-uniform secrets, such as biometrics, by relying only on non-robust public storage. In the past, such constructions were known only in the random oracle model, or required the entropy rate of the secret to be greater than half. Our construction relies on a randomly chosen common reference string (CRS) available to all parties.

Chaoping Xing - One of the best experts on this subject based on the ideXlab platform.

  • optimal Algebraic Manipulation detection codes in the constant error model
    Theory of Cryptography Conference, 2015
    Co-Authors: Ronald Cramer, Carles Padro, Chaoping Xing
    Abstract:

    Algebraic Manipulation detection (AMD) codes, introduced at EUROCRYPT 2008, may, in some sense, be viewed as keyless combinatorial authentication codes that provide security in the presence of an oblivious, Algebraic attacker. Its original applications included robust fuzzy extractors, secure message transmission and robust secret sharing. In recent years, however, a rather diverse array of additional applications in cryptography has emerged. In this paper we consider, for the first time, the regime of arbitrary positive constant error probability e in combination with unbounded cardinality M of the message space. There are several applications where this model makes sense. Adapting a known bound to this regime, it follows that the binary length ρ of the tag satisfies ρ ≥ loglogM + Ω e (1). In this paper, we shall call AMD codes meeting this lower bound optimal. Known constructions, notably a construction based on dedicated polynomial evaluation codes, are a multiplicative factor 2 off from being optimal. By a generic enhancement using error-correcting codes, these parameters can be further improved but remain suboptimal. Reaching optimality efficiently turns out to be surprisingly nontrivial. We propose a novel constructive method based on symmetries of codes. This leads to an explicit construction based on certain BCH codes that improves the parameters of the polynomial construction and to an efficient randomized construction of optimal AMD codes based on certain quasi-cyclic codes. In all our results, the error probability e can be chosen as an arbitrarily small positive real number.

  • optimal Algebraic Manipulation detection codes in the constant error model
    2014
    Co-Authors: Ronald Cramer, Carles Padro, Chaoping Xing
    Abstract:

    Algebraic Manipulation detection (AMD) codes, introduced at EUROCRYPT 2008, may, in some sense, be viewed as keyless combinatorial authentication codes that provide security in the presence of an oblivious, Algebraic attacker. Its original applications included robust fuzzy extractors, secure message transmission and robust secret sharing. In recent years, however, a rather diverse array of additional applications in cryptography has emerged. In this paper we consider, for the first time, the regime of arbitrary positive constant error probability e in combination with unbounded cardinality M of the message space. There are several applications where this model makes sense. Adapting a known bound to this regime, it follows that the binary length ρ of the tag satisfies ρ ≥ log logM +Ωe(1). In this paper, we shall call AMD codes meeting this lower bound optimal. Known constructions, notably a construction based on dedicated polynomial evaluation codes, are a multiplicative factor 2 off from being optimal. By a generic enhancement using error-correcting codes, these parameters can be further improved but remain suboptimal. Reaching optimality efficiently turns out to be surprisingly nontrivial. Owing to our refinement of the mathematical perspective on AMD codes, which focuses on symmetries of codes, we propose novel constructive principles. This leads to an explicit construction based on certain BCH codes that improves the parameters of the polynomial construction and to an efficient randomized construction of optimal AMD codes based on certain quasi-cyclic codes. In all our results, the error probability e can be chosen as an arbitrarily small positive real number.

Carles Padro - One of the best experts on this subject based on the ideXlab platform.

  • optimal Algebraic Manipulation detection codes in the constant error model
    Theory of Cryptography Conference, 2015
    Co-Authors: Ronald Cramer, Carles Padro, Chaoping Xing
    Abstract:

    Algebraic Manipulation detection (AMD) codes, introduced at EUROCRYPT 2008, may, in some sense, be viewed as keyless combinatorial authentication codes that provide security in the presence of an oblivious, Algebraic attacker. Its original applications included robust fuzzy extractors, secure message transmission and robust secret sharing. In recent years, however, a rather diverse array of additional applications in cryptography has emerged. In this paper we consider, for the first time, the regime of arbitrary positive constant error probability e in combination with unbounded cardinality M of the message space. There are several applications where this model makes sense. Adapting a known bound to this regime, it follows that the binary length ρ of the tag satisfies ρ ≥ loglogM + Ω e (1). In this paper, we shall call AMD codes meeting this lower bound optimal. Known constructions, notably a construction based on dedicated polynomial evaluation codes, are a multiplicative factor 2 off from being optimal. By a generic enhancement using error-correcting codes, these parameters can be further improved but remain suboptimal. Reaching optimality efficiently turns out to be surprisingly nontrivial. We propose a novel constructive method based on symmetries of codes. This leads to an explicit construction based on certain BCH codes that improves the parameters of the polynomial construction and to an efficient randomized construction of optimal AMD codes based on certain quasi-cyclic codes. In all our results, the error probability e can be chosen as an arbitrarily small positive real number.

  • optimal Algebraic Manipulation detection codes in the constant error model
    2014
    Co-Authors: Ronald Cramer, Carles Padro, Chaoping Xing
    Abstract:

    Algebraic Manipulation detection (AMD) codes, introduced at EUROCRYPT 2008, may, in some sense, be viewed as keyless combinatorial authentication codes that provide security in the presence of an oblivious, Algebraic attacker. Its original applications included robust fuzzy extractors, secure message transmission and robust secret sharing. In recent years, however, a rather diverse array of additional applications in cryptography has emerged. In this paper we consider, for the first time, the regime of arbitrary positive constant error probability e in combination with unbounded cardinality M of the message space. There are several applications where this model makes sense. Adapting a known bound to this regime, it follows that the binary length ρ of the tag satisfies ρ ≥ log logM +Ωe(1). In this paper, we shall call AMD codes meeting this lower bound optimal. Known constructions, notably a construction based on dedicated polynomial evaluation codes, are a multiplicative factor 2 off from being optimal. By a generic enhancement using error-correcting codes, these parameters can be further improved but remain suboptimal. Reaching optimality efficiently turns out to be surprisingly nontrivial. Owing to our refinement of the mathematical perspective on AMD codes, which focuses on symmetries of codes, we propose novel constructive principles. This leads to an explicit construction based on certain BCH codes that improves the parameters of the polynomial construction and to an efficient randomized construction of optimal AMD codes based on certain quasi-cyclic codes. In all our results, the error probability e can be chosen as an arbitrarily small positive real number.

  • detection of Algebraic Manipulation with applications to robust secret sharing and fuzzy extractors
    International Cryptology Conference, 2008
    Co-Authors: Ronald Cramer, Carles Padro, Yevgeniy Dodis, Serge Fehr, Daniel Wichs
    Abstract:

    Consider an abstract storage device Σ(G) that can hold a single element x from a fixed, publicly known finite group G. Storage is private in the sense that an adversary does not have read access to Σ(G) at all. However, Σ(G) is non-robust in the sense that the adversary can modify its contents by adding some offset Δ ∈ G. Due to the privacy of the storage device, the value Δ can only depend on an adversary's a priori knowledge of x. We introduce a new primitive called an Algebraic Manipulation detection (AMD) code, which encodes a source s into a value x stored on Σ(G) so that any tampering by an adversary will be detected. We give a nearly optimal construction of AMD codes, which can flexibly accommodate arbitrary choices for the length of the source s and security level. We use this construction in two applications: - We show how to efficiently convert any linear secret sharing scheme into a robust secret sharing scheme, which ensures that no unqualified subset of players can modify their shares and cause the reconstruction of some value s′ ≠ s. - We show how to build nearly optimal robust fuzzy extractors for several natural metrics. Robust fuzzy extractors enable one to reliably extract and later recover random keys from noisy and non-uniform secrets, such as biometrics, by relying only on non-robust public storage. In the past, such constructions were known only in the random oracle model, or required the entropy rate of the secret to be greater than half. Our construction relies on a randomly chosen common reference string (CRS) available to all parties.

Ovaskainen Otso - One of the best experts on this subject based on the ideXlab platform.

  • A unified framework for analysis of individual-based models in ecology and beyond
    Nature Communications, 2020
    Co-Authors: Cornell, Stephen J., Suprunenko, Yevhen F., Finkelshtein Dmitri, Somervuo Panu, Ovaskainen Otso
    Abstract:

    Abstract: Individual-based models, ‘IBMs’, describe naturally the dynamics of interacting organisms or social or financial agents. They are considered too complex for mathematical analysis, but computer simulations of them cannot give the general insights required. Here, we resolve this problem with a general mathematical framework for IBMs containing interactions of an unlimited level of complexity, and derive equations that reliably approximate the effects of space and stochasticity. We provide software, specified in an accessible and intuitive graphical way, so any researcher can obtain analytical and simulation results for any particular IBM without Algebraic Manipulation. We illustrate the framework with examples from movement ecology, conservation biology, and evolutionary ecology. This framework will provide unprecedented insights into a hitherto intractable panoply of complex models across many scientific fields

  • A unified framework for analysis of individual-based models in ecology and beyond
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Cornell, Stephen J., Suprunenko, Yevhen F., Finkelshtein Dmitri, Somervuo Panu, Ovaskainen Otso
    Abstract:

    Individual-based models, 'IBMs', describe naturally the dynamics of interacting organisms or social or financial agents. They are considered too complex for mathematical analysis, but computer simulations of them cannot give the general insights required. Here, we resolve this problem with a general mathematical framework for IBMs containing interactions of an unlimited level of complexity, and derive equations that reliably approximate the effects of space and stochasticity. We provide software, specified in an accessible and intuitive graphical way, so any researcher can obtain analytical and simulation results for any particular IBM without Algebraic Manipulation. We illustrate the framework with examples from movement ecology, conservation biology, and evolutionary ecology. This framework will provide unprecedented insights into a hitherto intractable panoply of complex models across many scientific fields.Peer reviewe

Cornell, Stephen J. - One of the best experts on this subject based on the ideXlab platform.

  • A unified framework for analysis of individual-based models in ecology and beyond
    Nature Communications, 2020
    Co-Authors: Cornell, Stephen J., Suprunenko, Yevhen F., Finkelshtein Dmitri, Somervuo Panu, Ovaskainen Otso
    Abstract:

    Abstract: Individual-based models, ‘IBMs’, describe naturally the dynamics of interacting organisms or social or financial agents. They are considered too complex for mathematical analysis, but computer simulations of them cannot give the general insights required. Here, we resolve this problem with a general mathematical framework for IBMs containing interactions of an unlimited level of complexity, and derive equations that reliably approximate the effects of space and stochasticity. We provide software, specified in an accessible and intuitive graphical way, so any researcher can obtain analytical and simulation results for any particular IBM without Algebraic Manipulation. We illustrate the framework with examples from movement ecology, conservation biology, and evolutionary ecology. This framework will provide unprecedented insights into a hitherto intractable panoply of complex models across many scientific fields

  • A unified framework for analysis of individual-based models in ecology and beyond
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Cornell, Stephen J., Suprunenko, Yevhen F., Finkelshtein Dmitri, Somervuo Panu, Ovaskainen Otso
    Abstract:

    Individual-based models, 'IBMs', describe naturally the dynamics of interacting organisms or social or financial agents. They are considered too complex for mathematical analysis, but computer simulations of them cannot give the general insights required. Here, we resolve this problem with a general mathematical framework for IBMs containing interactions of an unlimited level of complexity, and derive equations that reliably approximate the effects of space and stochasticity. We provide software, specified in an accessible and intuitive graphical way, so any researcher can obtain analytical and simulation results for any particular IBM without Algebraic Manipulation. We illustrate the framework with examples from movement ecology, conservation biology, and evolutionary ecology. This framework will provide unprecedented insights into a hitherto intractable panoply of complex models across many scientific fields.Peer reviewe