The Experts below are selected from a list of 33669 Experts worldwide ranked by ideXlab platform

Matthew Mckeon - One of the best experts on this subject based on the ideXlab platform.

Robert I. Soare - One of the best experts on this subject based on the ideXlab platform.

  • The history and Concept of computability
    1999
    Co-Authors: Robert I. Soare
    Abstract:

    We consider the Informal Concept of a “computable ” or “effectively calculable” function on natural numbers and two of the formalisms used to define it, computability” and “(general) recursiveness. ” We consider their origin, exact technical definition, Concepts, history, how they became fixed in their present roles, and ho

  • Computability and Recursion
    1996
    Co-Authors: Robert I. Soare
    Abstract:

    We consider the Informal Concept of "computability" or "effective calculability" and two of the formalisms commonly used to define it, "(Turing) computability" and "(general) recursiveness." We consider their origin, exact technical definition, Concepts, history, general English meanings, how they became fixed in their present roles, how they were first and are now used, their impact on nonspecialists, how their use will affect the future content of the subject of computability theory, and its connection to other related areas

  • Computability and Recursion
    1996
    Co-Authors: Robert I. Soare
    Abstract:

    . We consider the Informal Concept of "computability" or "effective calculability" and two of the formalisms commonly used to define it, "(Turing) computability" and "(general) recursiveness". We consider their origin, exact technical definition, Concepts, history, general English meanings, how they became fixed in their present roles, how they were first and are now used, their impact on nonspecialists, how their use will affect the future content of the subject of computability theory, and its connection to other related areas. After a careful historical and Conceptual analysis of computability and recursion we make several recommendations in section §7 about preserving the intensional differences between the Concepts of "computability" and "recursion". Specifically we recommend that: the term "recursive" should no longer carry the additional meaning of "computable" or "decidable"

  • Computability and Recursion
    1996
    Co-Authors: Robert I. Soare
    Abstract:

    We consider the Informal Concept of "computability" or "effective calculability" and two of the formalisms commonly used to define it, "(Turing) computability" and "(general) recursiveness." We consider their origin, exact technical definition, Concepts, history, general English meanings, how they became fixed in their present roles, how they were first and are now used, their impact on nonspecialists, how their use will affect the future content of the subject of computability theory, and its connection to other related areas. After a careful historical and Conceptual analysis of computability and recursion we make several recommendations in section #7 about preserving the intensional differences between the Concepts of "computability" and "recursion." Specifically we recommend that: the term "recursive" should no longer carry the additional meaning of "computable" or "decidable", functions defined using Turing machines, register machines, or their variants should be called ico..

  • Computability and recursion
    1996
    Co-Authors: Robert I. Soare
    Abstract:

    We consider the Informal Concept of “computability” or “effective calculability” and two of the formalisms commonly used to define it, “(Turing) computability” and “(general) recursiveness.” We consider their origin, exact technical definition, Concepts, history, general English meanings, how they became fixed in their present roles, how they were first and are now used, their impact on nonspecialists, how their use will affect the future content of the subject of computability theory, and its connection to other related areas. After a careful historical and Conceptual analysis of computability and recursion we make several recommendations in section §7 about preserving the intensional differences between the Concepts of “computability” and “recursion.” Specifically we recommend that: the term “recursive ” should no longer carry the additional meaning of “computable” or “decidable;” functions defined using Turing machines, register machines, or their variants should be called “computable” rather than “recursive;” we should distinguish the intensional difference between Church’s Thesis and Turing’s Thesis, and use the latter particularly in dealing with mechanistic questions; the name of the subject should be “Computability Theory” or simply Computability rather tha

Robert Harper - One of the best experts on this subject based on the ideXlab platform.

  • Structure and Efficiency of Computer Programs
    2018
    Co-Authors: Robert Harper
    Abstract:

    Much fundamental research in computer science is driven by two complementary notions of beauty in programming, that arising from the structure of a program and that arising from the efficiency of an algorithm. As Lewin famously said, “there’s nothing so practical as good theory” [Marrow, 1984]. Decades of experience has borne out the remarkable efficacy of theory in improving the practice of programming. Programming language theory is the study of the structural aspects of programming. The central notion is that of compositionality, the construction of a program by composition of separable parts. Results are formulated in terms of programming languages defined by type systems, which mediate composition of components, and semantics, which determines the execution behavior of those programs. Notable theorems include the parametricity theorem, which provides the mathematical foundation for the Informal Concept of data abstraction. Algorithm theory is the study of the efficiency aspects of programming. The central notion is of asymptotic analysis of the time and space usage of a program, expressed in terms of a size measure or a probability distribution on the inputs. Results are formulated in terms of machine models of computation, such as TM’s or RAM’s, which define the basic steps of an algorithm and their exceution cost, perhaps relative to parameters such as the number of processors on a PRAM. Algorithms are expressed in “high-level assembler”, a simple imperative programming language, for which the translation to the “official” machine model is readily understood. Often algorithms are expressed in terms of explicit representations of data structures using “pointers” and “words” to manage storage. By and large the algorithms and programming languages communities operate in isolation from one another. Programming languages researchers focus on the practicalities of building large software systems, and are seldom concerned about efficiency. Algorithms researchers focus on the efficiency of core programming techniques, and are seldom concerned about composition. (These are, of course, caricatures of reality, but it seems to me that they contain an element of truth.)

Vladimir A. Zakharov - One of the best experts on this subject based on the ideXlab platform.

  • Zakharov “On the Possibility of Provably Secure Obfuscating Programs
    2003
    Co-Authors: Nikolay P. Varnovsky, Vladimir A. Zakharov
    Abstract:

    Abstract. By obfuscation we mean any efficient semantic-preserving transformation of computer programs aimed at bringing a program into such a form, which impedes the understanding of its algorithm and data structures or prevents the extracting of some valuable information from the plaintext of a program. The main difficulty in designing an effective program obfuscator is to guarantee security, i.e. to prove that no algorithm can break software protection in reasonable time. All obfuscation techniques and tools developed so far rely on the Informal Concept of security and therefore can’t be regarded as provably secure. In this paper we (1) introduce for the first time a formal information-theoretic definition of obfuscation security, (2) present a new obfuscation technique which takes advantage of cryptographic primitives (one-way functions, hard-core predicates), and (3) demonstrate, taking a conventional password identification scheme as a case study, how to prove security of the obfuscating transformations

Nikolay P. Varnovsky - One of the best experts on this subject based on the ideXlab platform.

  • Zakharov “On the Possibility of Provably Secure Obfuscating Programs
    2003
    Co-Authors: Nikolay P. Varnovsky, Vladimir A. Zakharov
    Abstract:

    Abstract. By obfuscation we mean any efficient semantic-preserving transformation of computer programs aimed at bringing a program into such a form, which impedes the understanding of its algorithm and data structures or prevents the extracting of some valuable information from the plaintext of a program. The main difficulty in designing an effective program obfuscator is to guarantee security, i.e. to prove that no algorithm can break software protection in reasonable time. All obfuscation techniques and tools developed so far rely on the Informal Concept of security and therefore can’t be regarded as provably secure. In this paper we (1) introduce for the first time a formal information-theoretic definition of obfuscation security, (2) present a new obfuscation technique which takes advantage of cryptographic primitives (one-way functions, hard-core predicates), and (3) demonstrate, taking a conventional password identification scheme as a case study, how to prove security of the obfuscating transformations