Proceedings of the nineteenth annual ACM symposium on Theory of computing最新文献

Two tapes are better than one for off-line Turing machines 对于离线的图灵机来说，两盘磁带比一盘要好

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28406

W. Maass, G. Schnitger, E. Szemerédi

引用次数: 22

A new approach to all pairs shortest paths in planar graphs 平面图中全对最短路径的一种新方法

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28398

G. Frederickson

引用次数: 14

Fast parallel algorithms for chordal graphs 弦图的快速并行算法

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28433

J. Naor, M. Naor, A. Schäffer

引用次数: 70

The decision problem for the probabilities of higher-order properties 高阶属性概率的决策问题

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28441

Phokion G. Kolaitis, Moshe Y. Vardi

{"title":"The decision problem for the probabilities of higher-order properties","authors":"Phokion G. Kolaitis, Moshe Y. Vardi","doi":"10.1145/28395.28441","DOIUrl":"https://doi.org/10.1145/28395.28441","url":null,"abstract":"The probability of a property on the class of all finite relational structures is the limit as n → ∞ of the fraction of structures with n elements satisfying the property, provided the limit exists. It is known that 0-1 laws hold for any property expressible in first-order logic or in fixpoint logic, i.e. the probability of any such property exists and is either 0 or 1. It is also known that the associated decision problem for the probabilities is PSPACE-complete and EXPTIME-complete for first-order logic and fixpoint logic respectively. The 0-1 law fails, however, in general for second-order properties and the decision problem becomes unsolvable. We investigate here logics which on the one hand go beyond fixpoint in terms of expressive power and on the other possess the 0-1 law. We consider first iterative logic which is obtained from first order logic by adding while looping as a construct. We show that the 0-1 law holds for this logic and determine the complexity of the associated decision problem. After this we study a fragment of second order logic called strict &Sgr;11. This class of properties is obtained by restricting appropriately the first-order part of existential second-order sentences. Every strict &Sgr;11 property is NP-computable and there are strict &Sgr;11 properties that are NP-complete, such as 3-colorability. We show that the 0-1 law holds for strict &Sgr;11 properties and establish that the associated decision problem is NEXPTIME-complete. The proofs of the decidability and complexity results require certain combinatorial machinery, namely generalizations of Ramsey's Theorem.","PeriodicalId":161795,"journal":{"name":"Proceedings of the nineteenth annual ACM symposium on Theory of computing","volume":"278 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115970554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 95

Zero knowledge proofs of identity 零知识身份证明

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28419

U. Feige, A. Fiat, A. Shamir

引用次数: 175

Towards a theory of software protection and simulation by oblivious RAMs 基于遗忘ram的软件保护与仿真理论研究

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28416

Oded Goldreich

{"title":"Towards a theory of software protection and simulation by oblivious RAMs","authors":"Oded Goldreich","doi":"10.1145/28395.28416","DOIUrl":"https://doi.org/10.1145/28395.28416","url":null,"abstract":"Software protection is one of the most important issues concerning computer practice. There exist many heuristics and ad-hoc methods for protection, but the problem as a whole has not received the theoretical treatment it deserves. In this paper, we make the first steps towards a theoretic treatment of software protection: First, we distill and formulate the key problem of learning about a program from its execution. Second, assuming the existence of one-way permutations, we present an efficient way of executing programs such that it is infeasible to learn anything about the program by monitoring its executions. How can one efficiently execute programs without allowing an adversary, monitoring the execution, to learn anything about the program? Traditional cryptographic techniques can be applied to keep the contents of the memory unknown throughout the execution, but are not applicable to the problem of hiding the access pattern. The problem of hiding the access pattern efficiently corresponds to efficient simulation of Random Access Machines (RAM) on an oblivious RAM. We define an oblivious RAM to be a (probabilistic) RAM for which (the distribution of) the memory access pattern is independent of the input. We present an (on-line) simulation of t steps of an arbitrary RAM with m memory cells, by less than t·m&egr; steps of an oblivious RAM with 2m memory cells, where &egr;>0 is an arbitrary constant.","PeriodicalId":161795,"journal":{"name":"Proceedings of the nineteenth annual ACM symposium on Theory of computing","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129534507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 524

On learning Boolean functions 关于布尔函数的学习

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28427

B. Natarajan

引用次数: 146

Dynamic parallel complexity of computational circuits 计算电路的动态并行复杂性

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28423

G. Miller, S. Teng

引用次数: 30

Searching a two key table under a single key 在单个键下搜索两个键表

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28436

J. Munro

引用次数: 9

Some consequences of the existence of pseudorandom generators 伪随机发生器存在的一些结果

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28412

E. Allender

引用次数: 43