| dc.description.abstract | The key-Jock-pair mechanism based on the Chinese remainder theorem was modified and implemented on the single-key-lock system. The singlekey- Jock system associates each subJect<i.e., user) with a key and each obJect( i.e., file) with a Jock. The modification is inspired by Chang�s method of key-Jock-paJr mechanism using the Chinese Remainder Theorem. In addition to using the key-Jock-pair (KLP) mechanism based on the Chinese remainder theorem, we introduce a hierarchical key storage structure which not only implies the relationship between the subJects, but decreases the number of recalculations of keys substantially when obJects are added or deleted. This hierarchical key storage structure also requ1res fewer files or lock numbers to be involved in the key calculation. It also reduces the verit" icat JOn time to Q( log2n), instead of OUog2N) which the old SKL system needs. Morever, during the calculation of keys for the subJects, faster computation speed 1s achJeved by using the modulus congruence of a Di, n where Dj =II Li for i = J and j = 1, 2, ... , n i=l where Li denotes the Jock on the t"i Je i for i= 1, 2, 3, ... , n. A simulation of the single-key-lock access control was perfomed on a Vax/Unix machine and time complexity of the key calculation was discussed. | |
