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Security Applications of Formal Language Theory
Dartmouth College Dartmouth Digital Commons Computer Science Technical Reports Computer Science 11-25-2011 Security Applications of Formal Language Theory Len Sassaman Dartmouth College Meredith L. Patterson Dartmouth College Sergey Bratus Dartmouth College Michael E. Locasto Dartmouth College Anna Shubina Dartmouth College Follow this and additional works at: https://digitalcommons.dartmouth.edu/cs_tr Part of the Computer Sciences Commons Dartmouth Digital Commons Citation Sassaman, Len; Patterson, Meredith L.; Bratus, Sergey; Locasto, Michael E.; and Shubina, Anna, "Security Applications of Formal Language Theory" (2011). Computer Science Technical Report TR2011-709. https://digitalcommons.dartmouth.edu/cs_tr/335 This Technical Report is brought to you for free and open access by the Computer Science at Dartmouth Digital Commons. It has been accepted for inclusion in Computer Science Technical Reports by an authorized administrator of Dartmouth Digital Commons. For more information, please contact [email protected]. Security Applications of Formal Language Theory Dartmouth Computer Science Technical Report TR2011-709 Len Sassaman, Meredith L. Patterson, Sergey Bratus, Michael E. Locasto, Anna Shubina November 25, 2011 Abstract We present an approach to improving the security of complex, composed systems based on formal language theory, and show how this approach leads to advances in input validation, security modeling, attack surface reduction, and ultimately, software design and programming methodology. We cite examples based on real-world security flaws in common protocols representing different classes of protocol complexity. We also introduce a formalization of an exploit development technique, the parse tree differential attack, made possible by our conception of the role of formal grammars in security. These insights make possible future advances in software auditing techniques applicable to static and dynamic binary analysis, fuzzing, and general reverse-engineering and exploit development. -
Privacy Enhancing Technologies for the Internet III: Ten Years Later
Privacy Enhancing Technologies for the Internet III: Ten Years Later Ian Goldberg David R. Cheriton School of Computer Science University of Waterloo Waterloo, ON [email protected] 1 Introduction In 1997 with Wagner and Brewer, and again in 2002, we looked at the then-current state of privacy-enhancing technologies (PETs) for the Internet. [27, 26] Now, in 2007, we take a third look. Technologies to help users maintain their privacy online are as important today as ever before—if not more so. Identity theft is the fastest-growing crime in the US today [47] and it is all too easy for would-be identity thieves to harvest personal information from the online trails Internet users leave every day. Losses of large databases of personal information are an almost daily occurrence [2]; for example, retailers’ servers are penetrated [44], databases are traded between government and private companies [36] and laptops containing social security numbers are stolen [35]. In 1997, we discussed the dossier effect: all available information about a person gets cross-referenced, and the resulting dossier ends up being used for many purposes, lawful and not. This practice has expanded over the years; the companies that compile and sell these dossiers are known as data brokers. Choicepoint is a prime example—in 2005, this data broker sold dossiers on over 150,000 Americans to a group of criminals. [10] The PETs we discuss here give people a way to control how much of their personal information is revealed when they use the Internet. By controlling the spread of this information, they can limit the size of the data brokers’ dossiers about them. -
Studying the Anonymity Trilemma with a Discrete-Event Mix Network Simulator Ania M
Studying the anonymity trilemma with a discrete-event mix network simulator Ania M. Piotrowska Nym Technologies ABSTRACT strategies on the example of Elixxir [2], HOPR [4] and Nym [1]. To In this work, we present a discrete event mix network simulator, the best of our knowledge, this is a first such empirical analysis of which allows analysing how anonymity, latency, and bandwidth those networking designs. overhead are affected by various scenarios of deployment and de- sign choices. These design choices include network topology, mix- 2 BACKGROUND ing technique, volume of traffic, latency requirements, packet size or use of cover traffic. To the best of our knowledge, this isthe The concept of an anonymous communication network was pio- first such simulator as work on it began in 2017 to analyze the neered by Chaum [7] to mitigate the threats of progressive com- Loopix mix network, and the code of our simulator is available munications surveillance. Their main security goal is to shield the under an open-source license. To demonstrate the capabilities of correspondence between senders and recipients by hiding the dis- our simulator, we perform an empirical analysis of the impact of tinctive characteristics of the network traffic, the so called metadata. core design choices on anonymity, scalability and latency in Elixxir, The principal concept of the Chaum’s anonymous communication HOPR and Nym, currently deployed mix network infrastructures network is the decentralized mix network in which the network that make a variety of different choices in their design. traffic is relayed via a set of independently operated cryptographic relays called mix nodes. -
The Pynchon Gate
The Pynchon Gate A Secure Method of Pseudonymous Mail Retrieval Len Sassaman Bram Cohen Nick Mathewson Katholieke Universiteit Leuven BitTorrent The Free Haven Project [email protected] [email protected] [email protected] ABSTRACT ter [48] or Mixminion [22]) to send authenticated requests to We describe the Pynchon Gate, a practical pseudonymous a nym server, which delivers outgoing messages to the email message retrieval system. Our design uses a simple distributed- network and handles administrative commands. The nym trust private information retrieval protocol to prevent ad- server also receives incoming messages and passes them to a versaries from linking recipients to their pseudonyms, even collator component, which encrypts the messages and peri- when some of the infrastructure has been compromised. This odically packages them into regular batches. These batches approach resists global traffic analysis significantly better are then replicated at a number of distributor servers, which than existing deployed pseudonymous email solutions, at the use a private information retrieval protocol to allow nym cost of additional bandwidth. We examine security concerns owners to receive mail while maintaining unlinkability be- raised by our model, and propose solutions. tween a message and its recipient. 1.0.1 Goals. Categories and Subject Descriptors First, our design must be secure: we want the Pynchon C.2.4 [Distributed Systems]: Client/server Gate to resist active and passive attacks at least as well as General Terms the state of the art for forward message anonymity. Thus, we should try to protect users’ identities from a global eaves- Design, Security dropper for as long as possible; to hinder active attackers Keywords who can delay, delete, or introduce traffic; and to resist an attacker who has compromised some (but not all) of the anonymity, mix networks, private information retrieval servers on the network. -
Curriculum Vitae – Ross Anderson
Curriculum Vitae – Ross Anderson I am Professor of Security Engineering at Cambridge University, and a Fellow of Churchill College. Security Engineering is about building systems to remain depend- able in the face of malice, error or mischance. As a discipline, it focuses on the tools, processes and methods needed to design, implement and test complete systems, and to adapt existing systems as their environment evolves. My mission has been building security engineering into a discipline. Twenty-five years ago, some parts of it – cryptography, protocols and operating system security – had well-developed theory, but the experts mostly didn’t talk to each other. Other aspects, such as software security, were a practitioners’ art, while yet other aspects such as hardware security were just black magic. Since 1992 I’ve started research programs in neglected areas, ranging from hard- ware security through API security and signal processing to security economics. I’ve worked on applications from payments through online medical records to curfew tags, and documented their failure modes so that engineers can learn from them. I wrote the standard textbook, ‘Security Engineering – A Guide to Building Dependable Dis- tributed Systems’ of which the first edition came out in 2001 [88] and the second in 2008 [157]; I’m working on the third which should ship in 2020 (most of the chapters are already online on my website). Along the way I’ve contributed to the design of a number of widely-deployed systems, from the STS specification for prepayment utility meters (with 60 million installed) to the HomePlug standard for power-line communi- cations (widely used to extend wifi). -
No Right to Remain Silent: Isolating Malicious Mixes Hemi Leibowitz, Bar-Ilan University, IL; Ania M
No Right to Remain Silent: Isolating Malicious Mixes Hemi Leibowitz, Bar-Ilan University, IL; Ania M. Piotrowska and George Danezis, University College London, UK; Amir Herzberg, University of Connecticut, US https://www.usenix.org/conference/usenixsecurity19/presentation/leibowitz This paper is included in the Proceedings of the 28th USENIX Security Symposium. August 14–16, 2019 • Santa Clara, CA, USA 978-1-939133-06-9 Open access to the Proceedings of the 28th USENIX Security Symposium is sponsored by USENIX. No Right to Remain Silent: Isolating Malicious Mixes Hemi Leibowitz Ania M. Piotrowska George Danezis Bar-Ilan University, Israel University College London, UK University College London, UK Amir Herzberg University of Connecticut, US Abstract network is an example of anonymity systems that protect the meta-data. Tor is currently the most popular system offering Mix networks are a key technology to achieve network anonymity, attracting almost 2 million users daily. However, anonymity and private messaging, voting and database as research has shown [47, 40, 42, 41], Tor offers limited lookups. However, simple mix network designs are vulner- security guarantees against traffic analysis. able to malicious mixes, which may drop or delay packets The need for strong anonymity systems resulted in re- to facilitate traffic analysis attacks. Mix networks with prov- newed interest in onion mixnets [12]. In an onion mixnet, able robustness address this drawback through complex and sender encrypts a message multiple times, using the public expensive proofs of correct shuffling but come at a great cost keys of the destination and of multiple mixes. Onion mixnets and make limiting or unrealistic systems assumptions. -
Privacy and Data Protection by Design – from Policy to Engineering December 2014
Privacy and Data Protection by Design – from policy to engineering December 2014 European Union Agency for Network and Information Security www.enisa.europa.eu Privacy and Data Protection by Design – from policy to engineering December 2014 About ENISA The European Union Agency for Network and Information Security (ENISA) is a centre of network and information security expertise for the EU, its member states, the private sector and Europe’s citizens. ENISA works with these groups to develop advice and recommendations on good practice in infor- mation security. It assists EU member states in implementing relevant EU legislation and works to improve the resilience of Europe’s critical information infrastructure and networks. ENISA seeks to enhance existing expertise in EU member states by supporting the development of cross-border com- munities committed to improving network and information security throughout the EU. More infor- mation about ENISA and its work can be found at www.enisa.europa.eu. Authors George Danezis, Josep Domingo-Ferrer, Marit Hansen, Jaap-Henk Hoepman, Daniel Le Métayer, Rodica Tirtea, Stefan Schiffner Contact For contacting the authors please use [email protected] For media enquires about this paper, please use [email protected]. Acknowledgements We have discussed this work with numerous people at various occasions; we thank for the valuable input we got from these discussions. While we cannot name all, we would like to thank Sébastien Gambs and Rosa Barcelo for their feedback on drafts of this report. Legal notice Notice must be taken that this publication represents the views and interpretations of the authors and edi- tors, unless stated otherwise. -
Privacy Enhancing Technologies for the Internet III: Ten Years Later∗
Privacy Enhancing Technologies for the Internet III: Ten Years Later∗ Ian Goldberg David R. Cheriton School of Computer Science University of Waterloo Waterloo, ON [email protected] 1 Introduction In 1997 with Wagner and Brewer, and again in 2002, we looked at the then-current state of privacy-enhancing technologies (PETs) for the Internet. [27, 26] Now, in 2007, we take a third look. Technologies to help users maintain their privacy online are as important today as ever before—if not more so. Identity theft is the fastest-growing crime in the US today [47] and it is all too easy for would-be identity thieves to harvest personal information from the online trails Internet users leave every day. Losses of large databases of personal information are an almost daily occurrence [2]; for example, retailers’ servers are penetrated [44], databases are traded between government and private companies [36] and laptops containing social security numbers are stolen [35]. In 1997, we discussed the dossier effect: all available information about a person gets cross-referenced, and the resulting dossier ends up being used for many purposes, lawful and not. This practice has expanded over the years; the companies that compile and sell these dossiers are known as data brokers. Choicepoint is a prime example—in 2005, this data broker sold dossiers on over 150,000 Americans to a group of criminals. [10] The PETs we discuss here give people a way to control how much of their personal information is revealed when they use the Internet. By controlling the spread of this information, they can limit the size of the data brokers’ dossiers about them. -
Phd Thesis, ETH Z¨Urich, 1997
Guessing human-chosen secrets Joseph Bonneau University of Cambridge Churchill College May 2012 This dissertation is submitted for the degree of Doctor of Philosophy Declaration This dissertation is the result of my own work and includes nothing which is the outcome of work done in collaboration except where specifically indicated in the text. No parts of this dissertation have been submitted for any other qualification. This dissertation does not exceed the regulation length of 60; 000 words, including tables and footnotes. To Fletcher, for teaching me the value of hard work. I'm glad you're back. |Joseph Bonneau, May 2012 Acknowledgements I am grateful to my supervisor Ross Anderson for help every step of the way, from answering my emails when I was a foreign undergraduate to pushing me to finally finish the dissertation. He imparted countless research and life skills along the way, in addition to helping me learn to write in English all over again. I was also fortunate to be surrounded in Cambridge by a core group of \security people" under Ross' leadership willing to ask the sceptical questions needed to understand the field. In particular, I've benefited from the mentorship of Frank Stajano and Markus Kuhn, the other leaders of the group, as well as informal mentorship from Richard Clayton, Bruce Christianson, Mike Bond, George Danezis, Claudia Diaz, Robert Watson and Steven Murdoch amongst many others. I thank Arvind Narayanan for his support and mentorship from afar. I am most appreciative of the personal mentorship extended to me by Saar Drimer through my years in the lab, which always pushed me to be more honest about my own work. -
2013-07-08-Security Researchers Amicus.Pdf
Case: 13-1816 Document: 003111316712 Page: 1 Date Filed: 07/08/2013 No. 13-1816 In the United States Court of Appeals for the Third Circuit United States of America, Plaintiff-Appellee, v. Andrew Auernheimer, Defendant-Appellant. Appeals from the United States District Court for the District of New Jersey, Case No. 11-CR-470, Judge Susan D. Wigenton Brief of Meredith Patterson, Brendan O’Connor, Sergey Bratus, Gabriella Coleman, Peyton Engel, Matthew Green, Dan Hirsch, Dan Kaminsky, Samuel Liles, Shane MacDougall, Brian Martin, C. Thomas, and Peiter Zatko as Amici Curiae Supporting Appellant Alex Muentz Adjunct Instructor Department of Criminal Justice Gladfelter Hall, 5th floor Temple University 1115 Polett Walk Philadelphia PA 19122 (215) 806-4383 Case: 13-1816 Document: 003111316712 Page: 2 Date Filed: 07/08/2013 Table of Contents Interest of Amici Curiae .......................1 Non-Party Statement .........................2 Consent to File ............................2 Summary of Argument.........................2 Argument................................3 1 Allowing a corporation to serve data publicly, then state after the fact that access was secretly restricted and thus impose criminal liability, amounts to a private criminal law, and may also violate the Ex Post Facto Clause. ...............................3 2 Criminalizing access to publicly-offered material is not in the public in- terest, because it prevents the security research community from exer- cising its consumer-protecting role. .................. 16 Conclusion............................... 21 Certificate of Bar Membership.................... 23 Certificate of Compliance With Word Count Requirements ... 23 Certificate of Service ........................ 23 Certificate of Identical Compliance of Briefs ........... 24 Certificate of Virus Check ...................... 24 ii Case: 13-1816 Document: 003111316712 Page: 3 Date Filed: 07/08/2013 Table of Authorities Cases Calder v. -
Toward an Information Theoretic Secure Anonymous Communication Service the Pynchon Gate Pseudonymous Mail System
Toward an Information Theoretic Secure Anonymous Communication Service The Pynchon Gate Pseudonymous Mail System Len Sassaman1, Nick Mathewson2, Brian Warner3, Bram Cohen4, and Bart Preneel1 1 Katholieke Universiteit Leuven Kasteelpark Arenberg 10, B-3001 Leuven-Heverlee, Belgium flen.sassaman,[email protected] 2 The Free Haven Project [email protected] 3 Allmydata, Inc. 555 De Haro Street, Suite 400, San Francisco CA, 94107 USA [email protected] 4 BitTorrent, Inc. 201 Mission Street, Suite 900, San Francisco, CA 94105 [email protected] Abstract. We describe the Pynchon Gate, a practical pseudonymous message retrieval system. Our design uses a simple distributed-trust pri- vate information retrieval protocol to prevent adversaries from linking recipients to their pseudonyms, even when some of the infrastructure has been compromised. This approach resists global traffic analysis sig- nificantly better than existing deployed pseudonymous email solutions, at the cost of additional bandwidth. This design improves upon previous versions by being resistant to Byzantine servers. We provide a review of related work, and evaluate it in comparison to our approach. We exam- ine security concerns raised by our model,and propose solutions. Special emphasis is placed on ease of implementation and deployment of the system, as well as end-user usability issues. 1 Introduction Over the last several decades, there have been numerous systems proposed which aim to preserve the anonymity of the recipient of some data. Some have involved trusted third-parties or trusted hardware; others have been constructed on top of link-layer anonymity systems or mix networks. Pseudonymous messaging services allow users to send messages that originate at a pseudonymous address (or \nym") unlinked to the user, and to receive mes- sages sent to that address, without allowing an attacker to deduce which users are associated with which pseudonyms. -
Financial Technology
Journal APEX 2016 AWARD WINNER FINANCIAL TECHNOLOGY Available to download at CAPCO.COM/INSTITUTE #44 11.2016 EMPOWERING THE [FINANCIAL] WORLD Pushing the pace of Financial Technology, together we’ll help our clients solve technology challenges for their business – whether it’s capital markets in Mumbai or community banking in Macon. We leverage knowledge and insights from our clients around the world: clients in towns everywhere are becoming 20,000 more efficient, modern and scalable. transactions processed help solve clients’ 27 billion challenges — big and small. moved across the globe in a single year $9 trillion empowers our clients’ communities to build storefronts, homes and careers. hearts and minds have joined forces to 55,000 bring you greater capabilities in even the smallest places. Empowering the Financial World FISGLOBAL.COM © 2016 FIS and/or its subsidiaries. All Rights Reserved. The Capco Institute Journal of Financial Transformation Recipient of the Apex Award for Publication Excellence Editor Shahin Shojai, Global Head, Capco Institute Advisory Board Christine Ciriani, Partner, Capco Chris Geldard, Partner, Capco Nick Jackson, Partner, Capco Editorial Board Franklin Allen, Nippon Life Professor of Finance, University of Pennsylvania Joe Anastasio, Partner, Capco Philippe d’Arvisenet, Adviser and former Group Chief Economist, BNP Paribas Rudi Bogni, former Chief Executive Officer, UBS Private Banking Bruno Bonati, Chairman of the Non-Executive Board, Zuger Kantonalbank Dan Breznitz, Munk Chair of Innovation Studies, University of Toronto Urs Birchler, Professor Emeritus of Banking, University of Zurich Géry Daeninck, former CEO, Robeco Stephen C. Daffron, CEO, Interactive Data Jean Dermine, Professor of Banking and Finance, INSEAD Douglas W.