The Power of the Context
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Towards a Secure Agent Society
Towards A Secure Agent So ciety Qi He Katia Sycara The Rob otics Institute The Rob otics Institute Carnegie Mellon University Carnegie Mellon University Pittsburgh, PA 15213, U.S.A. Pittsburgh, PA 15213, U.S.A [email protected] [email protected] March 23, 1998 Abstract We present a general view of what a \secure agent so ciety" should b e and howtode- velop it rather than fo cus on any sp eci c details or particular agent-based application . We b elieve that the main e ort to achieve security in agent so cieties consists of the following three asp ects:1 agent authentication mechanisms that form the secure so ciety's foundation, 2 a security architecture design within an agent that enables security p olicy making, se- curity proto col generation and security op eration execution, and 3 the extension of agent communication languages for agent secure communication and trust management. In this pap er, all of the three main asp ects are systematically discussed for agent security based on an overall understanding of mo dern cryptographic technology. One purp ose of the pap er is to give some answers to those questions resulting from absence of a complete picture. Area: Software Agents Keywords: security, agent architecture, agent-based public key infrastructure PKI, public key cryptosystem PKCS, con dentiality, authentication, integrity, nonrepudiation. 1 1 Intro duction If you are going to design and develop a software agent-based real application system for elec- tronic commerce, you would immediately learn that there exists no such secure communication between agents, which is assumed by most agent mo del designers. -
The Future: the Story of Squeak, a Practical Smalltalk Written in Itself
Back to the future: the story of Squeak, a practical Smalltalk written in itself Dan Ingalls, Ted Kaehler, John Maloney, Scott Wallace, and Alan Kay [Also published in OOPSLA ’97: Proc. of the 12th ACM SIGPLAN Conference on Object-oriented Programming, 1997, pp. 318-326.] VPRI Technical Report TR-1997-001 Viewpoints Research Institute, 1209 Grand Central Avenue, Glendale, CA 91201 t: (818) 332-3001 f: (818) 244-9761 Back to the Future The Story of Squeak, A Practical Smalltalk Written in Itself by Dan Ingalls Ted Kaehler John Maloney Scott Wallace Alan Kay at Apple Computer while doing this work, now at Walt Disney Imagineering 1401 Flower Street P.O. Box 25020 Glendale, CA 91221 [email protected] Abstract Squeak is an open, highly-portable Smalltalk implementation whose virtual machine is written entirely in Smalltalk, making it easy to debug, analyze, and change. To achieve practical performance, a translator produces an equivalent C program whose performance is comparable to commercial Smalltalks. Other noteworthy aspects of Squeak include: a compact object format that typically requires only a single word of overhead per object; a simple yet efficient incremental garbage collector for 32-bit direct pointers; efficient bulk- mutation of objects; extensions of BitBlt to handle color of any depth and anti-aliased image rotation and scaling; and real-time sound and music synthesis written entirely in Smalltalk. Overview Squeak is a modern implementation of Smalltalk-80 that is available for free via the Internet, at http://www.research.apple.com/research/proj/learning_concepts/squeak/ and other sites. It includes platform-independent support for color, sound, and image processing. -
1. Course Information Are Handed Out
6.826—Principles of Computer Systems 2006 6.826—Principles of Computer Systems 2006 course secretary's desk. They normally cover the material discussed in class during the week they 1. Course Information are handed out. Delayed submission of the solutions will be penalized, and no solutions will be accepted after Thursday 5:00PM. Students in the class will be asked to help grade the problem sets. Each week a team of students Staff will work with the TA to grade the week’s problems. This takes about 3-4 hours. Each student will probably only have to do it once during the term. Faculty We will try to return the graded problem sets, with solutions, within a week after their due date. Butler Lampson 32-G924 425-703-5925 [email protected] Policy on collaboration Daniel Jackson 32-G704 8-8471 [email protected] We encourage discussion of the issues in the lectures, readings, and problem sets. However, if Teaching Assistant you collaborate on problem sets, you must tell us who your collaborators are. And in any case, you must write up all solutions on your own. David Shin [email protected] Project Course Secretary During the last half of the course there is a project in which students will work in groups of three Maria Rebelo 32-G715 3-5895 [email protected] or so to apply the methods of the course to their own research projects. Each group will pick a Office Hours real system, preferably one that some member of the group is actually working on but possibly one from a published paper or from someone else’s research, and write: Messrs. -
April 22 -- STEPS NSF 2012 Report
! 2012 REPORT ! STEPS Toward Expressive Programming Systems ! “A#Science#Experiment”# ! by# (In#random#order)#Yoshiki#Ohshima,#Dan#Amelang,#Ted#Kaehler,#Bert#Freudenberg,# Aran#Lunzer,#Alan#Kay,#Ian#Piumarta,#Takashi#Yamamiya,#Alan#Borning,#Hesam# Samimi,#Bret#Victor,#Kim#Rose*# VIEWPOINTS#RESEARCH#INSTITUTE# # # *These#are#the#STEPS#researchers#for#the#year#2012.#For#a#complete#listing# of#the#participants#over#the#length#of#the#project#see#the#section#on#the# NSF#site#which#contains#this#report.# TABLE OF CONTENTS — The STEPS Project for the General Public Summary of the STEPS project . Origin . STEPS aims at personal computing . What does STEPS look like? . STEPS is a “science project” . General approach . “T-shirt programming” . Overall map of STEPS . General STEPS results . Making “runnable maths” . Assessing STEPS Summary of STEPS research in 2012 . Inventing & building a language for STEPS “UI and applications”, and rewriting Frank in it . Producing a workable “chain of meaning” that extends from the screen all the way to the CPU . Inventing methods that create automatic visualizers for languages created from metalanguages . Continuing the start of “What vs How” programming via “Cooperating Languages and Solvers” Reflections on the STEPS Project to Date References Outreach Activities for final year of NSF part of the STEPS project Publications for the NSF part of the STEPS project Appendix I: KScript and KSWorld Appendix II: Making Applications in KSWorld ——— ! The$STEPS$Project$For$The$General$Public$ If#computing#is#important—for#daily#life,#learning,#business,#national#defense,#jobs,#and# -
Computer Organization and Design
THIRD EDITION Computer Organization Design THE HARDWARE/SOFTWARE INTERFACE ACKNOWLEDGEMENTS Figures 1.9, 1.15 Courtesy of Intel. Computers in the Real World: Figure 1.11 Courtesy of Storage Technology Corp. Photo of “A Laotian villager,” courtesy of David Sanger. Figures 1.7.1, 1.7.2, 6.13.2 Courtesy of the Charles Babbage Institute, Photo of an “Indian villager,” property of Encore Software, Ltd., India. University of Minnesota Libraries, Minneapolis. Photos of “Block and students” and “a pop-up archival satellite tag,” Figures 1.7.3, 6.13.1, 6.13.3, 7.9.3, 8.11.2 Courtesy of IBM. courtesy of Professor Barbara Block. Photos by Scott Taylor. Figure 1.7.4 Courtesy of Cray Inc. Photos of “Professor Dawson and student” and “the Mica micromote,” courtesy of AP/World Wide Photos. Figure 1.7.5 Courtesy of Apple Computer, Inc. Photos of “images of pottery fragments” and “a computer reconstruc- Figure 1.7.6 Courtesy of the Computer History Museum. tion,” courtesy of Andrew Willis and David B. Cooper, Brown University, Figure 7.33 Courtesy of AMD. Division of Engineering. Figures 7.9.1, 7.9.2 Courtesy of Museum of Science, Boston. Photo of “the Eurostar TGV train,” by Jos van der Kolk. Figure 7.9.4 Courtesy of MIPS Technologies, Inc. Photo of “the interior of a Eurostar TGV cab,” by Andy Veitch. Figure 8.3 ©Peg Skorpinski. Photo of “firefighter Ken Whitten,” courtesy of World Economic Forum. Figure 8.11.1 Courtesy of the Computer Museum of America. Graphic of an “artificial retina,” © The San Francisco Chronicle. -
The Development of Smalltalk Topic Paper #7
The Development of Smalltalk Topic Paper #7 Alex Laird Max Earn Peer CS-3210-01 Reviewer On Time/Format 1 2/4/09 Survey of Programming Languages Correct 5 Spring 2009 Clear 2 Computer Science, (319) 360-8771 Concise 2 [email protected] Grading Rubric Grading Total 10 pts ABSTRACT Dynamically typed languages are easier on the compiler because This paper describes the development of the Smalltalk it has to make fewer passes and the brunt of checking is done on programming language. the syntax of the code. Compilation of Smalltalk is just-in-time compilation, also known Keywords as dynamic translation. It means that upon compilation, Smalltalk code is translated into byte code that is interpreted upon usage and Development, Smalltalk, Programming, Language at that point the interpreter converts the code to machine language and the code is executed. Dynamic translations work very well 1. INTRODUCTION with dynamic typing. Smalltalk, yet another programming language originally developed for educational purposes and now having a much 5. IMPLEMENTATIONS broader horizon, first appeared publically in the computing Smalltalk has been implemented in numerous ways and has been industry in 1980 as a dynamically-typed object-oriented language the influence of many future languages such as Java, Python, based largely on message-passing in Simula and Lisp. Object-C, and Ruby, just to name a few. Athena is a Smalltalk scripting engine for Java. Little Smalltalk 2. EARLY HISTORY was the first interpreter of the programming language to be used Development for Smalltalk started in 1969, but the language outside of the Xerox PARC. -
Smalltalk's Influence on Modern Programming
1 Smalltalk’s Influence on Modern Programming Smalltalk’s Influence on Modern Programming Matt Savona. February 1 st , 2008. In September 1972 at Xerox PARC, Alan Kay, Ted Kaeher and Dan Ingalls were discussing programming languages in the hallway of their office building. Ted and Dan had begun to consider how large a language had to be to have “great power.” Alan took a different approach, and “asserted that you could define the "most powerful language in the world" in "a page of code."” Ted and Dan replied, “Put up or shut up” (Kay). And with that, the bet to develop the most powerful language was on. Alan arrived at PARC every morning at 4am for two weeks, and devoted his time from 4am to 8am to the development of the language. That language was Smalltalk. Kay had “originally made the boast because McCarthy's self-describing LISP interpreter was written in itself. It was about "a page", and as far as power goes, LISP was the whole nine- yards for functional languages.” He was sure that he could “do the same for object-oriented languages” and still have a reasonable syntax. By the eighth morning, Kay had a version of Smalltalk developed where “symbols were byte-coded and the receiving of return-values from a send was symmetric” (Kay). Several days later, Dan Ingalls had coded Kay’s scheme in BASIC, added a “token scanner”, “list maker” and many other features. “Over the next ten years he made at least 80 major releases of various flavors of Smalltalk” (Kay). -
Oral History of Butler Lampson
Oral History of Butler Lampson Interviewed by: Alan Kay Recorded: August 22, 2006 Cambridge, Mass. CHM Reference number: X3697.2007 © 2006 Computer History Museum Oral History of Butler Lampson Alan Kay: Part of my job here as given by the Computer History Museum is to try and get a few good words from you that we could use as the opening blurb for your award from the Computer History Museum. But also to get an oral history. Butler Lampson: I was going to say, I thought the job was to record hours of brilliant conversation that historians in 2100 will pore over. Kay: That is your job. My job is to only to try and instigate it. My theory about this thing is that you should not try and talk short. Lampson: Well, we’ve got lots of time right? Kay: Okay. We do have lots of time and tape is cheap. Lampson: Tape is cheap. Right. My sister’s a film editor and she hates it. She says things were much better in the days when film was expensive, because people would think about what they shot. Now, she says, they shoot hundreds of hours of crap and then they expect the editor to sort it out. Kay: We have to transcribe those hundreds of hours. Lampson: Yeah. Somebody’s got to look at it, it’s got to be fussed around with, and besides, she says, frequently in the whole of hundreds of hours you don’t find what you want because nobody thought about it beforehand. Kay: You remember Bonnie, my wife, ran a film and video company for ten years. -
The Cedar Programming Environment: a Midterm Report and Examination
The Cedar Programming Environment: A Midterm Report and Examination Warren Teitelman The Cedar Programming Environment: A Midterm Report and Examination Warren Teitelman t CSL-83-11 June 1984 [P83-00012] © Copyright 1984 Xerox Corporation. All rights reserved. CR Categories and Subject Descriptors: D.2_6 [Software Engineering]: Programming environments. Additional Keywords and Phrases: integrated programming environment, experimental programming, display oriented user interface, strongly typed programming language environment, personal computing. t The author's present address is: Sun Microsystems, Inc., 2550 Garcia Avenue, Mountain View, Ca. 94043. The work described here was performed while employed by Xerox Corporation. XEROX Xerox Corporation Palo Alto Research Center 3333 Coyote Hill Road Palo Alto, California 94304 1 Abstract: This collection of papers comprises a report on Cedar, a state-of-the-art programming system. Cedar combines in a single integrated environment: high-quality graphics, a sophisticated editor and document preparation facility, and a variety of tools for the programmer to use in the construction and debugging of his programs. The Cedar Programming Language is a strongly-typed, compiler-oriented language of the Pascal family. What is especially interesting about the Ce~ar project is that it is one of the few examples where an interactive, experimental programming environment has been built for this kind of language. In the past, such environments have been confined to dynamically typed languages like Lisp and Smalltalk. The first paper, "The Roots of Cedar," describes the conditions in 1978 in the Xerox Palo Alto Research Center's Computer Science Laboratory that led us to embark on the Cedar project and helped to define its objectives and goals. -
MVC Revival on the Web
MVC Revival on the Web Janko Mivšek [email protected] @mivsek @aidaweb ESUG 2013 Motivation 30 years of Smalltalk, 30 years of MVC 34 years exa!tly, sin!e "#$# %ot in JavaScri&t MVC frameworks 'or Sin(le)*age and +ealtime web a&&s ,e Smalltalkers s-ould respe!t and revive our &earls better Contents MVC e &lained %istory /sa(e in !.rrent JavaScri&t frameworks /sa(e in Smalltalk C.rrent and f.t.re MVC in 0ida/Web MVC Explained events Ar!hite!tural desi(n &attern - Model for domain s&e!ifi! data and logi! View updates Controller ) View for &resentation to t-e .ser ) Controller for intera!tions wit- t-e .ser UI and .&datin( domain model Domain changes Main benefit: actions observing ) se&aration of !on!erns Model MVC based on Observer pattern subscribe ) 3bserver looks at observee Observer changed - 3bservee is not aware of t-at s u 4e&enden!y me!-anism2 B t n - 3bserver is de&endent on 3bservee state e observing v - 3bservee m.st re&ort state !-an(es to 3bserver E b - *.b/S.b Event 6.s de!ou&les 3bservee from u S / 3bserver to &reserve its .nawarnes of observation b u changed P Observee Main benefit: (Observable) ) se&aration of !on!erns Multiple observers subscribe - M.lti&le observers of t-e same 3bservee Observer changed - 7n MVC an 3bservee is View and 3bservee is domain Model, t-erefore2 s u B t - many views of t-e same model n e observing v - many a&&s E b - many .sers u S / - mix of all t-ree !ases b u Observee changed P (Observable) Example: Counter demo in Aida/Web M.lti.ser realtime web !ounter exam&le -ttp://demo.aidaweb.si – !li!k Realtime on t-e left – !li!k De!rease or In!rease to c-an(e counter – !ounter is c-an(ed on all ot-er8s browsers History of MVC (1) 7nvented by 9rygve +eenska.g w-en -e worked in "#$:1$# wit- Alan ;ay's group on <ero *arc on Smalltalk and Dynabook – 'inal term Model)View)Controller !oined 10. -
Pharo by Example
Pharo by Example Andrew P. Black Stéphane Ducasse Oscar Nierstrasz Damien Pollet with Damien Cassou and Marcus Denker Version of 2009-10-11 ii This book is available as a free download from http://PharoByExample.org. Copyright © 2007, 2008, 2009 by Andrew P. Black, Stéphane Ducasse, Oscar Nierstrasz and Damien Pollet. The contents of this book are protected under Creative Commons Attribution-ShareAlike 3.0 Unported license. You are free: to Share — to copy, distribute and transmit the work to Remix — to adapt the work Under the following conditions: Attribution. You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under the same, similar or a compatible license. • For any reuse or distribution, you must make clear to others the license terms of this work. The best way to do this is with a link to this web page: creativecommons.org/licenses/by-sa/3.0/ • Any of the above conditions can be waived if you get permission from the copyright holder. • Nothing in this license impairs or restricts the author’s moral rights. Your fair dealing and other rights are in no way affected by the above. This is a human-readable summary of the Legal Code (the full license): creativecommons.org/licenses/by-sa/3.0/legalcode Published by Square Bracket Associates, Switzerland. http://SquareBracketAssociates.org ISBN 978-3-9523341-4-0 First Edition, October, 2009. -
Dynamic Object-Oriented Programming with Smalltalk
Dynamic Object-Oriented Programming with Smalltalk 1. Introduction Prof. O. Nierstrasz Autumn Semester 2009 LECTURE TITLE What is surprising about Smalltalk > Everything is an object > Everything happens by sending messages > All the source code is there all the time > You can't lose code > You can change everything > You can change things without restarting the system > The Debugger is your Friend © Oscar Nierstrasz 2 ST — Introduction Why Smalltalk? > Pure object-oriented language and environment — “Everything is an object” > Origin of many innovations in OO development — RDD, IDE, MVC, XUnit … > Improves on many of its successors — Fully interactive and dynamic © Oscar Nierstrasz 1.3 ST — Introduction What is Smalltalk? > Pure OO language — Single inheritance — Dynamically typed > Language and environment — Guiding principle: “Everything is an Object” — Class browser, debugger, inspector, … — Mature class library and tools > Virtual machine — Objects exist in a persistent image [+ changes] — Incremental compilation © Oscar Nierstrasz 1.4 ST — Introduction Smalltalk vs. C++ vs. Java Smalltalk C++ Java Object model Pure Hybrid Hybrid Garbage collection Automatic Manual Automatic Inheritance Single Multiple Single Types Dynamic Static Static Reflection Fully reflective Introspection Introspection Semaphores, Some libraries Monitors Concurrency Monitors Categories, Namespaces Packages Modules namespaces © Oscar Nierstrasz 1.5 ST — Introduction Smalltalk: a State of Mind > Small and uniform language — Syntax fits on one sheet of paper >