The Study and Development of New Schemes for Access Control
| Autor: | Kai-Yu Liu, 劉愷瑜 |
|---|---|
| Rok vydání: | 1999 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 87 In this thesis, we propose three new schemes for access control. The first method associates each user with four keys, while the second and third methods associate each user one key, respectively. The advantages of our proposed schemes are that the derivation of access rights is simple and the insertion, deletion and alternation of the user/file can be processed effectively. Moreover, the storage requirement of our schemes is small so that they can be adapted in practical application. In the first method, the main ideal is to remove the zero elements from the sparse access control matrixes. Hence, the key values and storage requirement is deduced greatly. There are four keys assigned to each user in this method. On the other hand, owing to the access operations are based on the expansions of key values in their binary representations, the scheme is very simple in dynamic operations. As for the second and third methods, they are both based on the variable-length codes. In these two schemes, each user is assigned one key which is composed of the variable-length codes corresponding to his access rights of all files. Hence, the storage requirement can be reduced via our methods. The features of these two schemes are that the operations are much easier than other methods. In particular, the third scheme is designed for the applications of sparse access control matrixes. The main results of our study are as follows. (1) We propose the ideal of removing the zero elements in access control matrix to develop a new access control scheme for reducing the key values and storage requirement. (2) We also proposed two new access control schemes, which are based on the variable-length codes with small required storage and simple dynamic operations. It is believed that the results of our study in this thesis will be much helpful to the future research in the areas of the access control. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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