February 1991 - Vol. 34 No. 2
Features
Personal computing: personal computers and the world software market
It may be trite to say that “the world is shrinking,” but it is true nonetheless. Political and technological changes are edging us in the direction of the global village. We have the economic unification of Western Europe, the transition of Eastern Europe to market economies, and free trade agreements and negotiations in the Western hemisphere. Blue jeans and rock and roll music are found throughout the world, we can direct dial to Iceland, and your grandmother may have a FAX machine.
Log on education: Quick, where do the computers go?
History has dealt computer and information science a special role in the inevitable restructuring of the educational system in the United States. In the coming decade computing and information technology will be the backbone of the most significant change in education in over 100 years. Rather than being an adjunct to learning and teaching, technology is facilitating a fundamental re-thinking of what should be learned and how. Such changes present the Communications readership with a unique opportunity and a serious responsibility. Toward meeting this challenge, in this column I will address some key issues in education and technology. For example, this first column examines how our basic notion of what needs to be learned is changing, and how this affects the ways in which technology is used. Subsequent columns will explore topics such as “programming's role in learning,” “multi-media, and nationwide, computer-based,” testing.
Much has been written about the necessity of processing data in the encrypted form. However, no satisfactory method of processing encrypted data has been published to date. Ahitub et al. [2] have analyzed the possibilities of using some special algorithms to add encrypted data. Rivest et al. [10] have suggested the use of an algorithm based on homomorphic functions for processing encrypted data. The main limitation of this algorithm is that such functions can be broken by solving a set of linear equations, as noted by [2]. The public-key crytosystem described in [11] can be used to multiply encrypted data but cannot be used to add encrypted data and is therefore not appropriate for some practical applications such as bank transactions. Abadi, Feigenbaum and Kilian [1] presented some general theorems concerning the problem of computing with encrypted data and formulated a framework to prove precise statements about what an encrypted instance hides and reveals; they also described encryption schemes for some well-known functions.
This note proposes an optimization to an algorithm published by T.E. Gerasch in his article “An Insertion Algorithm for a Minimal Internal Path Length Binary Search Tree” (Communications of the ACM, May 1988, pp. 579-585).
