Authentication in the Taos Operating System

Digital Equipment Corporation We describe a design for security in a distributed system and its implementation. In our design, applications gain access to security services through a narrow interface. This interface provides a notion of identity that includes simple principals, groups, roles, and delegations. A new operating system component manages principals, credentials, and secure channels. It checks credentials according to the formal rules of a logic of authentication. Our implementation is efficient enough to support a substantial user community

Network Objects

The charter of SRC is to advance both the state of knowledge and the state of the art in computer systems. From our establishment in 1984, we have performed basic and applied research to support Digital’s business objectives. Our current work includes exploring distributed personal computing on multiple platforms, networking, programming technology, system modelling and management techniques, and selected applications. Our strategy is to test the technical and practical value of our ideas by building hardware and software prototypes and using them as daily tools. Interesting systems are too complex to be evaluated solely in the abstract; extended use allows us to investigate their properties in depth. This experience is useful in the short term in refining our designs, and invaluable in the long term in advancing our knowledge. Most of the major advances in information systems have come through this strategy, including personal computing, distributed systems, and the Internet. We also perform complementary work of a more mathematical flavor. Some of it is in established fields of theoretical computer science, such as the analysis of algorithms, computational geometry, and logics of programming. Other work explores new ground motivated by problems that arise in our systems research

7 The Siphon: Managing Distant Replicated Repositories

This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for non-profit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of the Paris Research Laboratory of Digital Equipment Centre Technique Europe, in Rueil-Malmaison, France; an acknowledgement of the authors and individual contributors to the work; and all applicable portions of the copyright notice. Copying, reproducing, or republishing for any other purpose shall require a license with payment of fee to the Paris Research Laboratory. All rights reserved. ii The Siphon is intended to facilitate joint software development between groups working at distant sites connected by low bandwidth communication lines. It gives users the image of a single repository of individually manageable units, typically software or documentation components. Users can lock and modify each unit, the result being propagated automatically to all sites. The repository is replicated at each site, and possibly on multiple file servers for greater availability and reliability. A Siphon has been in operational use since January 198

Distributed Garbage Collection for Network Objects

In this report we present a fault-tolerant and efficient algorithm for distributed garbage collection and prove its correctness. The algorithm is a generalization of reference counting; it maintains a set of identifiers for processes with references to an object. The set is maintained with pair-wise communication between processes, so no global synchronization is required. The primary cost for maintaining the set is one remote procedure call when an object reference is transferred to a new process for the first time. The distributed collector collaborates with the local collector in detecting garbage; any local collector may be used, so long as it can be extended to provide notification when an object is collected. In fact, the distributed collector could be used without a local collector; in that case, the programmer would insert explicit dispose commands to release an object. The algorithm was designed and implemented as part of the Modula-3 network objects system, but it should be s..

Authentication in the Taos Operating System

This version was reconstructed from the printed version by OCR and han