Browsing by Author "YEH, YS"

Now showing 1 - 7 of 7

A CONFERENCE KEY DISTRIBUTION-SYSTEM BASED ON CROSS-PRODUCT
(1993-02-01)
WU, TC
;
YEH, YS
;
交大名義發表
;
資訊科學與工程研究所
;
National Chiao Tung University
Extended from the Diffie-Hellman public key distribution system (PKDS), we propose a conference key distribution system (CKDS) based on the cross-product operations on row vectors over a Galois field GF(P), where P is a prime number. In our CKDS, the chairperson computes a conference key CK and then embeds it to some public interpolating polynomials to let only the legal intended principals recover CK, while the illegal intended principals can not. From the public parameters, an intruder or any intended principal in the network does not know how many and who are the legal intended principals in the conference. Furthermore, since the construction of the CK does not interfere with the secret keys of the intended principals, any intended principals in the network has no useful information for revealing any other principals' secret keys. Besides, our CKDS can be implemented practically.
A NEW APPROACH TO DESIGN AND IMPLEMENTATION OF IBM PC FOR ACCESSING LIBRARY CD-ROM DATABASE VIA CAMPUS NETWORK
(1993)
CHEN, RS
;
CHEN, DJ
;
YEH, YS
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
A NEW HEURISTIC APPROACH FOR RELIABILITY OPTIMIZATION OF DISTRIBUTED COMPUTING SYSTEMS SUBJECT TO CAPACITY CONSTRAINTS
(1995-02-01)
CHEN, RS
;
CHEN, DJ
;
YEH, YS
;
交大名義發表
;
資訊科學與工程研究所
Distributed Computing Systems (DCS) have become a major trend in computer system design today, because of their high speed and reliable performance. Reliability is an important performance parameter in DCS design. In the reliability analysis of a DCS, the term of K-Node Reliability (KNR) is defined as the probability that all nodes in K (a subset of all processing elements) are connected. In this paper, we propose a simple, easily programmed heuristic method for obtaining the optimal design of a DCS in terms of maximizing reliability subject to a capacity constraint. The first part of this paper presents a heuristic algorithm which selects an optimal set of K-nodes that maximizes the KNR in a DCS subject to the capacity constraint. The second part of the paper describes a new approach that uses a K-tree disjoint reduction method to speed up the KNR evaluation. Compared with existing algorithms on various DCS topologies, the proposed algorithm finds a suboptimal design much more efficiently in terms of both execution time and space than an exact and exhaustive method for a large DCS.
ALGEBRAIC OPERATIONS ON ENCRYPTED RELATIONAL DATABASES
(1993-01-01)
WU, TC
;
YEH, YS
;
CHANG, CC
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
In this paper, we consider the problem of performing algebraic operations and their extensions with encrypted relational databases. Each tuple of a relation is enciphered by a cryptosystem based on the extended Chinese remainder theorem. We show that one can perform the Projection, the Cartesian Product and their composite operations, such as performing the Projection followed by the Cartesian Product and performing Cartesian Product followed by the Projection, with the encrypted tuples directly without deciphering them. We also show that there does not exist a secure way to protect data for performing Comparison operations, such as Selection, Union,... , etc., with encrypted relational databases.
AN AUTHENTICATION-COMBINED ACCESS-CONTROL SCHEME USING A ONE-WAY FUNCTION
(1994-03-01)
WU, TC
;
CHANG, CC
;
YEH, YS
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
In this paper, we propose an authentication-combined access control scheme for information protection systems. Let a(ij) be the access privilege of User i to File j. Initially, by the Diffie-Hellman public key distribution scheme, the system and the users are assigned distinct secret keys, and their corresponding public keys, respectively. Let K(s) be the secret key and y(s) be the public key of the system, and let K(i) be the secret key and y(i) be the public key of the User i. By using a predefined one-way function F, we compute r(ij) = F(K(i), y(s), a(ij)). Reversely, the access privilege can be retained as a(ij) = F(K(s), y(i), r(ij)). Being different from the previously proposed schemes, our scheme is safer and the user's secret key is used not only for computing the corresponding access privilege to the intended file, but also for authenticating the requesting user not to illegitimately access the protected files. The proposed scheme is simple to establish. Besides, it can perform the access control in dynamic environments, such as change access privileges and insert/delete users or files.
CRYPTOSYSTEM FOR SELECTIVELY BROADCASTING SEPARATE SECRETS
(1993-04-01)
WU, TC
;
YEH, YS
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
RELIABILITY OPTIMIZATION OF DISTRIBUTED COMPUTING SYSTEMS SUBJECT TO CAPACITY CONSTRAINTS
(1995-02-01)
CHEN, RS
;
CHEN, DJ
;
YEH, YS
;
交大名義發表
;
資訊科學與工程研究所
In this paper, we propose a simple, easily programmed exact method for obtaining the optimal design of a distributed computing system in terms of maximizing reliability subject to memory capacity constraints. We assume that a given amount of resources are available for linking the distributed computing system. The method is based on the partial order relation. To speed up the procedure, some rules are proposed to indicate conditions under which certain vectors in the numerical ordering that do not satisfy the capacity constraints can be skipped over. Simulation results show that the proposed algorithm requires less time and space than exhaustive method.