Results 1  10
of
13
The Protection of Information in Computer Systems
, 1975
"... This tutorial paper explores the mechanics of protecting computerstored information from unauthorized use or modification. It concentrates on those architectural structureswhether hardware or softwarethat are necessary to support information protection. The paper develops in three main sections ..."
Abstract

Cited by 618 (2 self)
 Add to MetaCart
This tutorial paper explores the mechanics of protecting computerstored information from unauthorized use or modification. It concentrates on those architectural structureswhether hardware or softwarethat are necessary to support information protection. The paper develops in three main sections. Section I describes desired functions, design principles, and examples of elementary protection and authentication mechanisms. Any reader familiar with computers should find the first section to be reasonably accessible. Section II requires some familiarity with descriptorbased computer architecture. It examines in depth the principles of modern protection architectures and the relation between capability systems and access control list systems, and ends with a brief analysis of protected subsystems and protected objects. The reader who is dismayed by either the prerequisites or the level of detail in the second section may wish to skip to Section III, which reviews the state of the art and current research projects and provides suggestions for further reading. Glossary The following glossary provides, for reference, brief definitions for several terms as used in this paper in the context of protecting information in computers. Access The ability to make use of information stored in a computer system. Used frequently as a verb, to the horror of grammarians. Access control list A list of principals that are authorized to have access to some object. Authenticate To verify the identity of a person (or other agent external to the protection system) making a request.
Discrete Logarithms in Finite Fields and Their Cryptographic Significance
, 1984
"... Given a primitive element g of a finite field GF(q), the discrete logarithm of a nonzero element u GF(q) is that integer k, 1 k q  1, for which u = g k . The wellknown problem of computing discrete logarithms in finite fields has acquired additional importance in recent years due to its appl ..."
Abstract

Cited by 87 (6 self)
 Add to MetaCart
Given a primitive element g of a finite field GF(q), the discrete logarithm of a nonzero element u GF(q) is that integer k, 1 k q  1, for which u = g k . The wellknown problem of computing discrete logarithms in finite fields has acquired additional importance in recent years due to its applicability in cryptography. Several cryptographic systems would become insecure if an efficient discrete logarithm algorithm were discovered. This paper surveys and analyzes known algorithms in this area, with special attention devoted to algorithms for the fields GF(2 n ). It appears that in order to be safe from attacks using these algorithms, the value of n for which GF(2 n ) is used in a cryptosystem has to be very large and carefully chosen. Due in large part to recent discoveries, discrete logarithms in fields GF(2 n ) are much easier to compute than in fields GF(p) with p prime. Hence the fields GF(2 n ) ought to be avoided in all cryptographic applications. On the other hand, ...
Password Authentication Schemes: Current Status and Key Issues
"... Password authentication is one of the simplest and the most convenient authentication mechanisms to deal with secret data over insecure networks. It is more frequently required in areas such as computer networks, wireless networks, remote login systems, operation systems, and database management sys ..."
Abstract

Cited by 6 (1 self)
 Add to MetaCart
Password authentication is one of the simplest and the most convenient authentication mechanisms to deal with secret data over insecure networks. It is more frequently required in areas such as computer networks, wireless networks, remote login systems, operation systems, and database management systems. In this paper, we shall present the result of our survey through all currently available passwordauthenticationrelated schemes and get them classified in terms of several crucial criteria. To be critical, most of the existing schemes are vulnerable to various attacks and fail to serve all the purposes an ideal password authentication scheme should. In order to see how different password authentication schemes compare in different situations, we define all possible attacks and goals that an ideal password authentication scheme should withstand and achieve. We should hope that the attacks and goals we offer here can also help future researchers develop better schemes.
IDbased SecretKey Cryptography
 ACM SIGOPS Operating Systems Review
, 1998
"... This paper introduces IDbased secretkey cryptography, in which secret keys are privately and uniquely binded to an identity. This enables to extend publickey cryptography features at the high throughput rate of secretkey cryptography. As applications, e#cient login protocols, an enhanced ver ..."
Abstract

Cited by 3 (0 self)
 Add to MetaCart
This paper introduces IDbased secretkey cryptography, in which secret keys are privately and uniquely binded to an identity. This enables to extend publickey cryptography features at the high throughput rate of secretkey cryptography. As applications, e#cient login protocols, an enhanced version of Kerberos, and an IDbased MAC algorithm are presented.
Honeywords: Making PasswordCracking Detectable
, 2013
"... Version 2.0 We suggest a simple method for improving the security of hashed passwords: the maintenance of additional “honeywords” (false passwords) associated with each user’s account. An adversary who steals a file of hashed passwords and inverts the hash function cannot tell if he has found the pa ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
Version 2.0 We suggest a simple method for improving the security of hashed passwords: the maintenance of additional “honeywords” (false passwords) associated with each user’s account. An adversary who steals a file of hashed passwords and inverts the hash function cannot tell if he has found the password or a honeyword. The attempted use of a honeyword for login sets off an alarm. An auxiliary server (the “honeychecker”) can distinguish the user password from honeywords for the login routine, and will set off an alarm if a honeyword is submitted.
A User Efficient Fair Blind Signature Scheme for Untraceable Electronic Cash
 Journal of Information Science and Engineering
"... Blind signatures have been widely adopted to construct untraceable electronic cash systems since they are both unlinkable and unforgeable. Although unlinkability protects the privacy of customers and users, it may be abused by criminals for such purposes as to launder money or to safely get a ransom ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
Blind signatures have been widely adopted to construct untraceable electronic cash systems since they are both unlinkable and unforgeable. Although unlinkability protects the privacy of customers and users, it may be abused by criminals for such purposes as to launder money or to safely get a ransom. The techniques of fair blind signatures are developed to deal with the abuse of unlinkability. In this paper we propose a user efficient fair blind signature scheme which makes it possible for a government or a judge to recover the link between a signature and the instance of the signing protocol which produces that signature when the unlinkability property is abused. Only two integers are required to form a signature in the proposed fair blind signature scheme. Furthermore, it only takes several modular multiplications for a user to obtain and verify a signature. It turns out that the scheme is suitable for situations where computation capability of users or customers is limited, such as smart cards and mobile units. Compared with existing blind signature schemes proposed in the literatures, our method reduces the computation required of users by more than 99%.
Construction and Categories of Codes
 Information Security and Privacy  Fifth Australasian Conference, ACISP 2000
, 2000
"... . Blakley and Borosh introduced a general theory of codes, encompassing cryptographic and error control codes among others. They explored the properties of such general codes with methods from relational algebra and set theory. We provide a categorical point of view, which leads to new constructions ..."
Abstract
 Add to MetaCart
. Blakley and Borosh introduced a general theory of codes, encompassing cryptographic and error control codes among others. They explored the properties of such general codes with methods from relational algebra and set theory. We provide a categorical point of view, which leads to new constructions of codes. We also exhibit a JordanH older type theorem and a Schreier refinement technique. 1 Introduction In the late twentieth century a vast proliferation of codes occurred. Many new cardinalities became common, especially large finite or infinite. Many new arithmetics  infinite as well as finite  could be found in the newly introduced arithmeticbased codes. Hilbert spaces are as integral to the theory of quantum error control as Hamming spaces to classical error control. But many new codes arose without arithmetic, amounting to mere codebooks or databases. Codes with no encode process, codes with no decode process, codes which encode every plaintext symbol into billions of di#eren...
Using Sparse Capabilities in a Distributed Operating System
, 1986
"... this paper we discuss a system, Amoeba, that uses capabilities for ..."
ALPS’07  Groups and Complexity
, 2007
"... The connection between groups and recursive (un)decidability has a long history, going back to the early 1900s. Also, various polynomialtime algorithms have been known in group theory for a long time. However the impact of more general computational complexity (e.g., NPcompleteness or PSpacecompl ..."
Abstract
 Add to MetaCart
The connection between groups and recursive (un)decidability has a long history, going back to the early 1900s. Also, various polynomialtime algorithms have been known in group theory for a long time. However the impact of more general computational complexity (e.g., NPcompleteness or PSpacecompleteness) has been relatively small and recent. These lectures review a sampling of older facts about algorithmic problems in group theory, and then present more recent results about the connection with complexity: isoperimetric functions and NP; Thompson groups, boolean circuits, and coNP; Thompson monoids and circuit complexity; Thompson groups, reversible computing, and #P; distortion of Thompson groups within Thompson monoids, and oneway permutations. We are especially interested in deep connections between computational complexity and group theory. By “connection ” we do not just mean analyzing the computational complexity of algorithms about groups. We are more interested in algebraic characterizations of complexity classes in terms of group theory, i.e., in finding a “mirror image” of all of complexity theory within group theory. Conversely, we are interested in the computational nature of concepts that appear at first purely algebraic.