DATA encryption, COMPUTER files, COMPUTER security, FILES (Records), CRYPTOGRAPHY, COMPUTERS
Abstract
Cryptographic techniques which can be used to maintain the confidentiality of information processed by computers are dealt with. Special emphasis is paid to the unique characteristics of computer files that make many cryptographic methods of little use. Relative security, costs, and preferred methods are included in this paper. [ABSTRACT FROM AUTHOR]
When the amount of space required for file storage exceeds the amount which can be kept online, decisions must be made as to which files are to be permanently resident and which mountable. These decisions will affect the number of mount requests issued to the operators. This is often a bottleneck in a computing facility, and reducing the number of mounts thus decreases turnaround time. An optimization model for the assignment of files to disk packs. and packs to either resident or nonresident status is presented. Heuristics are suggested for those cases in which it is inefficient to compute the actual optimum. [ABSTRACT FROM AUTHOR]
61 It is assumed that there is a similarity of function between the data names of a programming language and the file names of an operating system. The two functions are discussed in terms of the same basic concepts in order to identify the extent to which they overlap. It is suggested that there is some similarity between the idea of a file directory and a storable object of type context. Manipulations with contexts are then discussed at length. It is noted that there is a simple extension of Church's A notation that deals nicely with these ideas of context manipulation. Whereas a function can be regarded as the abstraction based upon the first two terms of the expression γ(namelist)(expression)(valuelist), it is found that a context can be viewed as an abstraction based upon the first two terms in the equivalent expression μ(namelist)(valuelist)(expression). [ABSTRACT FROM AUTHOR]
The design of a partial pass block sort with arbitrary range of key and number of work files is described. The design is a generalization of the Partial Pass Column Sort by Ashenhurst and the Amphisbaenic Sort by Nagler. The power of the sort is tabulated for various sizes of input file and number of work files. Consideration is given to the problem of combining a block sort with internal sorts, and to the best use of direct access storage devices. [ABSTRACT FROM AUTHOR]