An assessment of the U.S. government's EINSTEIN project.

We set out to build a public key cryptosystem by repeatedly substituting for variables in multivariate polynomials and simplifying the results to conceal the substitution process. There seems, however, to be no way to build such a system that is both secure and has a public key of practical size when the devices used to limit the number of coefficeints are nilpotence and J-rings. We have only shown, however, that it is impossible to produce such a system if the total degree of the encryption polynomial determines the size of the public key. Perhaps, by properly choosing p 0 and p 1, we can employ the fundamental scheme to produce sparse encrypting polynomials. Then the public key could be kept small while the encrypting polynomial bas large total degree and is difficult to invert.

In securing packet switched digital communications, it is possible to add the security measures at almost any layer of the Open Systems Interconnection (OSI) model of network functioning. At one extreme, security may be supplied either by physical protection of the communication links (with no impact at all on network communication protocols) or by independent encryption of the traffic on each link of the network (with little protocol impact). Solutions or this sort are called link security and, although widely employed, have the disadvantage of requiring the users to place a high degree of trust in the network. At the other extreme, it is possible, using cryptography, to add security to each individual user level application. This has the advantage of minimizing the user’s need to trust the network and thus providing end-to-end security, but also has the disadvantage of requiring a multiplicity of implementations.

article Free AccessCrypto policy perspectives Authors: Susan Landau Univ. of Massachusetts, Amherst Univ. of Massachusetts, AmherstView Profile , Stephen Kent Bolt Beranek and Newman Inc. Bolt Beranek and Newman Inc.View Profile , Clinton C. Brooks National Security Agency National Security AgencyView Profile , Scott Charney Dept. of Justice Dept. of JusticeView Profile , Dorothy E. Denning Georgetown Univ., Washington, DC Georgetown Univ., Washington, DCView Profile , Whitfield Diffie Sun Microsystems Sun MicrosystemsView Profile , Anthony Lauck Digital Equipment Corp. Digital Equipment Corp.View Profile , Douglas Miller Software Publishers Assoc. Software Publishers Assoc.View Profile , Peter G. Neumann ACM Committee on Computers and Public Policy, New York, NY ACM Committee on Computers and Public Policy, New York, NYView Profile , David L. Sobel Electronic Privacy Information Center (EPIC) Electronic Privacy Information Center (EPIC)View Profile Authors Info & Claims Communications of the ACMVolume 37Issue 8Aug. 1994 pp 115–121https://doi.org/10.1145/179606.179726Published:01 August 1994Publication History 10citation239DownloadsMetricsTotal Citations10Total Downloads239Last 12 Months13Last 6 weeks4 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

This paper presents a tutorial introduction to contemporary cryptography. The basic information theoretic and computational properties of classical and modern cryptographic systems are presented, followed by cryptanalytic examination of several important systems and an examination of the application of cryptography to the security of timesharing systems and computer networks. The paper concludes with a guide to the cryptographic literature.

For centuries, cryptography has been a valuable asset of the military and diplomatic communities. Indeed, it is so valuable that its practice has usually been shrouded in secrecy and mystery.