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Soumyadeep Ghosh will present his Pre-FPO, "Hardware Assurance with Pluggable Trust Architectures" on Friday, January 15, 2016 at 3:30pm in CS 301
by Nicki Gotsis 11 Jan '16

11 Jan '16

Soumyadeep Ghosh will present his Pre-FPO on Friday, January 15, 2016 at 3:30pm in CS 301. The members of his committee are David August (advisor), Andrew Appel and Aarti Gupta (readers), David Wentzlaff and Simha Sethumadhavan, Columbia University (non-readers). Everyone is invited to attend his talk. The talk title and abstract follow below: Title: Hardware Assurance with Pluggable Trust Architectures Abstract: Today, a user must take it on faith that their hardware and software providers have built a system which will not betray them to malicious actors. While significant research has been done on securing the software stack, these techniques all assume the presence of secure hardware. However, a number of factors such as incompleteness of techniques for verifying complex hardware designs, outsourcing and off-shoring of design and fabrication, and the incorporation of third-party components diminish confidence in the security of computer hardware. To address this problem, we propose a new architecture that allows users to select their own basis of trust in the system, independent of the device manufacturer. Trust is established via a pluggable and user-swappable hardware element called the Sentry. This pluggable-trust architecture isolates the effects of compromised hardware by allowing only the correctly executed results of signed software to be communicated externally. The basis of trust for the entire system is the Sentry, which acts as a gatekeeper and bridges the physical gap between the untrusted processor and any I/O device. The Sentry’s minimal effect on performance, the simplicity of its design, and its pluggability enable its production at an independent trusted fabrication plant. Its simplicity also makes the Sentry's verification tractable, giving the user choice in trust providers.

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Sarthak Grover will present his General Exam on Friday, January 8, 2016 in CS 302 at 2pm.
by Nicki Gotsis 06 Jan '16

06 Jan '16

Sarthak Grover will present his General Exam on Friday, January 8, 2016 in CS 302 at 2pm. The members of his committee are Nick Feamster (Adviser), Kyle Jamieson, and Jennifer Rexford. Everyone is invited to attend his talk, and those faculty wishing to remain for the oral exam following are welcome to do so. His abstract and reading list follow below. *Abstract* With a large increase in broadband services and capacity, it has become important to understand home network infrastructure and usage. Over the past two years, we have studied home network usage from two perspectives: the gateway and the ISP. In the first empirical study of home network availability, infrastructure, and usage, we deployed routers running custom firmware in multiple homes to collect measurements of home and Internet connectivity, as well as how users use their home network. Our results showed that half the home networks studied utilize less than half their available capacity. We followed up to this work by studying the relationship between traffic demand and service tier upgrades from the perspective of ISPs. In a unique controlled experiment, we compare two groups of Comcast subscribers from the same city: a control group (105 Mbps) and a randomly selected treatment group that was upgraded to 250 Mbps without their knowledge. We study how users who are already on service plans with high downstream throughput respond to a higher service tier (upgraded unknowingly), as compared to a similar control group. To our surprise, subscribers with moderate traffic demands increase their usage in response to a service-tier upgrade relatively more than high-volume subscribers do. We speculate that even though these users may not take advantage of the full available capacity, the service tier increase generally improves performance, which causes them to use the Internet more than they otherwise would have. *Reading List* 1. Bischof, Zachary S., Fabián E. Bustamante, and Rade Stanojevic. "Need, want, can afford: Broadband markets and the behavior of users." In Proceedings of the 2014 Conference on Internet Measurement Conference, pp. 73-86. ACM, 2014. 2. Kreibich, Christian, Nicholas Weaver, Boris Nechaev, and Vern Paxson. "Netalyzr: illuminating the edge network." In Proceedings of the 10th ACM SIGCOMM conference on Internet measurement, pp. 246-259. ACM, 2010. 3. Quan, Lin, John Heidemann, and Yuri Pradkin. "When the internet sleeps: correlating diurnal networks with external factors." In Proceedings of the 2014 Conference on Internet Measurement Conference, pp. 87-100. ACM, 2014. 4.Maier, Gregor, Anja Feldmann, Vern Paxson, and Mark Allman. "On dominant characteristics of residential broadband internet traffic." InProceedings of the 9th ACM SIGCOMM conference on Internet measurement conference, pp. 90-102. ACM, 2009. 5. Dicioccio, Lucas, Renata Teixeira, and Catherine Rosenberg. "Measuring home networks with homenet profiler." In Passive and Active Measurement, pp. 176-186. Springer Berlin Heidelberg, 2013. 6.Zheleva, Mariya, Paul Schmitt, Morgan Vigil, and Elizabeth Belding. "The increased bandwidth fallacy: performance and usage in rural zambia." InProceedings of the 4th Annual Symposium on Computing for Development, p. 2. ACM, 2013. 7.Cho, Kenjiro, Kensuke Fukuda, Hiroshi Esaki, and Akira Kato. "The impact and implications of the growth in residential user-to-user traffic." In ACM SIGCOMM Computer Communication Review, vol. 36, no. 4, pp. 207-218. ACM, 2006. 8.Paxson, Vern. "End-to-end routing behavior in the Internet." Networking, IEEE/ACM Transactions on 5, no. 5 (1997): 601-615. 9.Paxson, Vern. "Strategies for sound internet measurement." In Proceedings of the 4th ACM SIGCOMM conference on Internet measurement, pp. 263-271. ACM, 2004. 10.Calvert, Kenneth L., W. Keith Edwards, and Rebecca E. Grinter. "Moving Toward the Middle: The Case Against the End-to-End Argument in Home Networking." In HotNets. 2007. 11.Sundaresan, Srikanth, Walter De Donato, Nick Feamster, Renata Teixeira, Sam Crawford, and Antonio Pescapè. "Broadband internet performance: a view from the gateway." In ACM SIGCOMM computer communication review, vol. 41, no. 4, pp. 134-145. ACM, 2011. 12.Peterson, Larry L., and Bruce S. Davie. Computer networks: a systems approach. Elsevier, 2007. 13.Grover, Sarthak, Mi Seon Park, Srikanth Sundaresan, Sam Burnett, Hyojoon Kim, Bharath Ravi, and Nick Feamster. "Peeking behind the NAT: an empirical study of home networks." In Proceedings of the 2013 conference on Internet measurement conference, pp. 377-390. ACM, 2013. 14.Grover, Sarthak, Roya Ensafi, and Nick Feamster. “A case study of traffic demand response to broadband service-plan upgrades.” In Proceedings of the 2016 Passive and Active Measurement Conference. 2016.

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Soner Sevinc will present his FPO, "A Framework for Access Control and Resource Allocation in Federations" on Thursday, 1/14/2016 at 9am in CS 402
by Nicki Gotsis 05 Jan '16

05 Jan '16

Soner Sevinc will present his FPO, "A Framework for Access Control and Resource Allocation in Federations" on Thursday, 1/14/2016 at 9am in CS 402. The members of his committee are: Larry Peterson (adviser); Andy Bavier and Jennifer Rexford (readers); Michael Freedman and David Walker (nonreaders). A copy of his thesis is available in Room 310. Everyone is invited to attend his talk. The talk abstract follow below: ABSTRACT: In this thesis we address the access control and resource allocation problems in computational federations, such as testbeds and cloud computing federations. The computational federations of today are growing in their number of participant organizations, where one challenge is to allow organizations participate autonomously by expressing how much of their resources should be used and by whom, through complex policies. In addition, such organizations should be able to exchange resources with any other organizations without necessarily knowing all of them beforehand. We introduce our federation framework which allows to build federations in varying complexities easily, by synthesizing trust management, policy languages and resource discovery into a single system. Although these three have been studied separately in the past, we show that they are in fact related, and can be viewed as separate layers of a more general system. We argue that complex agreements that involve indirect trust relationships is one key way to enable resource exchange in a federation with numerous organizations, and this can be realized by our synthesis architecture that provides usability as well as expressiveness. As part of our framework, federation policy language (FPL) is used to express both the security and allocation policies, by providing simple primitives such as contracts that hide the underlying complexity. FPL primitives allow system administrators to express policies such as indirect trust and resource restrictions within the same construct. Underneath, FPL uses our distributed trust management system (CERTDIST) to implement and impose policy primitives. CERTDIST uses digital certificates to allow or deny resource requests and a DHT for complex distributive proofs in an e!cient way. The Resource discovery part of our framework (CODAL) is layered on top of FPL, and uses contracts to discover peers, FPL security and allocation policies to authorize for resources that are located possibly in many di↵erent organizations. We evaluate the federation framework with a realistic emulation of a large scale federation using real PlanetLab traces, that shows that complex policies can be expressed with a minimal amount of code, and we can e!ciently perform the access control and resource discovery operations in a federation.

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Ben Jones will present his Generals Exam on Tuesday, January 12, 2016 at 11am in CS 302.
by Nicki Gotsis 05 Jan '16

05 Jan '16

Ben Jones will present his Generals Exam on Tuesday, January 12, 2016 at 11am in CS 302. The members of his committee are: Nick Feamster (adviser), Andrew Appel, and Prateek Mittal. Everyone is invited to attend his talk, and those faculty wishing to remain for the oral exam following are welcome to do so. His abstract and reading list follow below. Abstract Censorship measurement is an important problem and social scientists, CS researchers, and advocacy groups all aim to discover what governments censor, how they restrict access, and how decisions about censorship vary across regions, countries, and time. Unfortunately, existing approaches cannot perform censorship measurements at a scale sufficient to answer these questions; worse, users must perform these measurements on-site, which is potentially risky due to the threat of retaliation against citizens who perform measurements. In my talk, I will present SPICE (Stealthy Panopticon for Internet Censorship Exploration) [7], a tool designed to measure censorship and evade the surveillance that puts users at risk. SPICE’s contributions are modeling censorship and surveillance, developing two strategies for reducing measurement risk, and implementing the measurements for one of these strategies. We model censorship based on existing work on the Great Firewall of China (GFC) and we model surveillance based on leaked Snowden documents and our campus IDS. We observe that surveillance and censorship systems have different goals, and thus certain types of measurement techniques may be able to characterize a censorship system without triggering a surveillance system. Although it is almost certainly impossible to eliminate risk (or even determine if we have succeeded in doing so), we posit that we may be able to reduce risk with measurement techniques that are difficult to observe or distinguish from innocuous network activity. Reading List Textbook: L. L. Peterson and B. S. Davie. Computer Networks, Fifth Edition: A Systems Approach. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 5th edition, 2011. Papers: [1] Anonymous. Towards a Comprehensive Picture of the Great Firewall’s DNS Censorship. In 4th USENIX Workshop on Free and Open Communications on the Internet (FOCI 14), San Diego, CA, Aug. 2014. USENIX Association. [2] A. Filasto` and J. Appelbaum. OONI: Open Observatory of Network Interference. In Presented as part of the 2nd USENIX Workshop on Free and Open Communications on the Internet, Berkeley, CA, 2012. USENIX. [3] J. Geddes, M. Schuchard, and N. Hopper. Cover Your ACKs: Pitfalls of Covert Channel Censorship Circumvention. In Proceedings of the 2013 ACM SIGSAC Conference on Computer &; Communications Security, CCS ’13, pages 361–372, New York, NY, USA, 2013. ACM. [4] A. Houmansadr, C. Brubaker, and V. Shmatikov. The Parrot is Dead: Observing unobservable network communications. In Proceedings of the 2013 IEEE Symposium on Security and Privacy, 2013. [5] B. Jones, R. Ensafi, N. Feamster, V. Paxson, and N. Weaver. Ethical concerns for censorship measurement. In Proceedings of the 2015 ACM SIGCOMM Workshop on Ethics in Networked Systems Research, pages 17–19. ACM, 2015. [6] B. Jones and N. Feamster. Can Censorship Measurements Be Safe(R)? In Proceedings of the 14th ACM Workshop on Hot Topics in Networks, HotNets-XIV, pages 1:1–1:7, New York, NY, USA, 2015. ACM. [7] M. Ku ̈hrer, T. Hupperich, J. Bushart, C. Rossow, and T. Holz. Going Wild: Large-Scale Classification of Open DNS Resolvers. In Proceedings of the 2015 ACM Conference on Internet Measurement Conference, IMC ’15, pages 355–368. ACM, 2015. [8] K. Schomp, T. Callahan, M. Rabinovich, and M. Allman. On Measuring the Client-side DNS Infrastructure. In Proceedings of the 2013 Conference on Internet Measurement Conference, IMC ’13, pages 77–90, New York, NY, USA, 2013. ACM. [9] W. Scott, S. Berg, and A. Krishnamurth. Satellite: Observations of the Internets Stars. Technical report, University of Washington, 2015. [10] A. Sfakianakis, E. Athanasopoulos, and S. Ioannidis. CensMon: A Web censorship monitor. In USENIX Workshop on Free and Open Communication on the Internet (FOCI), 2011.

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Xin Jin will present his Pre FPO on Monday, January 11, 2016 at 4pm in CS 302
by Nicki Gotsis 04 Jan '16

04 Jan '16

Xin Jin will present his Pre FPO on Monday, January 11, 2016 at 4pm in CS 302. The members of his committee are: Jennifer Rexford (adviser), David Walker (reader), Ratul Mahajan (Microsoft Research, reader), Nick Feamster (non-reader), Aarti Gupta (non-reader). Everyone is invited to attend his talk. The talk title and abstract follow below: Title: Dynamic management of software-defined networks Abstract: Network management is a difficult problem, since network administrators have to continuously update network configurations to alleviate congestion by routing more efficiently, to detect and block cyber-attacks, to perform planned maintenance, etc. Network updates are painful because operators unfortunately have to balance the tradeoff between the disruption caused by the problem (e.g., congestion and cyber-attacks), and the disruption introduced in fixing the problem. In this talk, I will present my research on building new network management systems that can (1) efficiently compose configuration updates from multiple network services, (2) quickly apply them to switches, and (3) effectively handle topology changes. I will first present CoVisor, a new kind of network hypervisor that enables, in a single network, the deployment of multiple network services written in different programming languages and operating on different controller platforms. CoVisor provides a simple API that allows network administrators to define the composition of multiple controllers, to choose the virtual topology exposed to each controller, and to constrain the packet handling capability of each controller. We developed a new set of efficient algorithms for composing controller applications and for compiling configurations of virtual networks into those of the physical network. We built a CoVisor prototype and showed that it is several orders of magnitude faster than a vanilla implementation without our optimizations. In the second part of the talk, I will present Dionysus, a new network update system that can quickly and consistently update network configurations. Dionysus uses a novel tool called a dependency graph to capture the dependencies between individual update operations. Based on the dependency graph, Dionysus dynamically schedules operations according to runtime conditions, and guarantees the consistency of the updates. We built a prototype of Dionysus and extensively evaluated it with testbed experiments and large-scale simulations. Results showed that Dionysus improves the median update speed by 53–88% as compared to prior methods. Finally, I will present Owan, a novel traffic management system that optimizes wide-area big data transfers with centralized joint control of the optical and network layers. Owan can dynamically change the network-layer topology by reconfiguring the optical devices. We developed efficient algorithms that dynamically reconfigure the optical circuits in the optical layer so that most transfers can use one or few hops in the network layer to reach their destinations. Testbed experiments and large-scale simulations showed that Owan completes big data transfers up to 4× faster on average, and up to 1.35× more transfers meet their deadlines, as compared to prior methods that only control the network layer.

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Yatin Manerkar will present his General Exam on Monday, January 11, 2016 at 2pm in CS 302
by Nicki Gotsis 04 Jan '16

04 Jan '16

Yatin Manerkar will present his General Exam on Monday, January 11, 2016 at 2pm in CS 302. The members of his committee are: Margaret Martonosi (adviser), Aarti Gupta, and David August. Everyone is invited to attend his talk, and those faculty wishing to remain for the oral exam following are welcome to do so. His abstract and reading list follow below. Title: CCICheck: Using µhb Graphs to Verify the Coherence-Consistency Interface Abstract: Memory consistency models define the rules that govern which values are visible to instructions of parallel programs. Today's multiprocessors are complex machines, and this complexity is set to increase in the future with increases in heterogeneity and system scale. As such, it can be difficult to comprehensively verify that a microarchitecture correctly implements the consistency model that it is supposed to. My research aims to conduct such microarchitectural consistency verification in a comprehensive and yet tractable manner. My work recently focused on bugs that occur due to the interaction of coherence and consistency at the coherence-consistency interface (CCI) of a microarchitecture. These bugs can be very subtle and difficult to detect. In this talk, I will discuss CCICheck, a methodology and tool for verifying a microarchitecture's implementation of a consistency model in a CCI-aware manner. CCICheck builds on the microarchitectural verification effort of the PipeCheck tool and methodology, but extends and generalizes it to be able to handle a much wider range of microarchitectures and ordering constraints. My work has used CCICheck to tractably model a variety of CCI scenarios, including partial incoherence, lazy coherence, and coherence protocol optimizations. Reading List: 1. John L. Hennessy and David A. Patterson. 2007. Computer Architecture, Fourth Edition: A Quantitative Approach. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA. 2. Daniel J. Sorin, Mark D. Hill, and David A. Wood. 2011. A Primer on Memory Consistency and Cache Coherence (1st ed.). Morgan & Claypool Publishers. 3. Daniel Lustig, Michael Pellauer, and Margaret Martonosi, “PipeCheck: Specifying and Verifying Microarchitectural Enforcement of Memory Consistency Models”, 47th International Symposium on Microarchitecture (MICRO), Cambridge, UK, December 2014. 4. Yatin A. Manerkar, Daniel Lustig, Michael Pellauer, and Margaret Martonosi. CCICheck: Using µhb Graphs to Verify the Coherence-Consistency Interface. The 48th Annual IEEE/ACM International Symposium on Microarchitecture (MICRO), December 2015. 5. Leslie Lamport. 1979. How to Make a Multiprocessor Computer That Correctly Executes Multiprocess Programs. IEEE Trans. Comput. 28, 9 (September 1979), 690-691. 6. Sarita V. Adve and Kourosh Gharachorloo. "Shared Memory Consistency Models: A Tutorial", Western Research Laboratory, Tech. Rep. 95/7, September 1995. 7. Hans-J. Boehm and Sarita V. Adve. 2008. Foundations of the C++ concurrency memory model. In Proceedings of the 2008 ACM SIGPLAN conference on Programming language design and implementation (PLDI '08). ACM, New York, NY, USA, 68-78. 8. Jade Alglave, Luc Maranget, and Michael Tautschnig. 2014. Herding Cats: Modelling, Simulation, Testing, and Data Mining for Weak Memory. ACM Trans. Program. Lang. Syst. 36, 2, Article 7 (July 2014), 74 pages. 9. Albert Meixner and Daniel J. Sorin, "Dynamic Verification of Memory Consistency in Cache-Coherent Multithreaded Computer Architectures," in Dependable and Secure Computing, IEEE Transactions on , vol.6, no.1, pp.18-31, Jan.-March 2009. 10. S. Hangal, D. Vahia, C. Manovit, J.-Y.J Lu, S. Narayanan, "TSOtool: a program for verifying memory systems using the memory consistency model," in Computer Architecture, 2004. Proceedings. 31st Annual International Symposium on , vol., no., pp.114-123, 19-23 June 2004.

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Arpit Gupta will present his Generals Exam on Thursday, January 07, 2016 at 3pm in CS 302
by Nicki Gotsis 04 Jan '16

04 Jan '16

Arpit Gupta will present his Generals Exam on Thursday, January 07, 2016 at 3pm in CS 302. The members of his committee are: Nick Feamster (adviser), Jennifer Rexford, and Andrew Appel. Everyone is invited to attend his talk, and those faculty wishing to remain for the oral exam following are welcome to do so. His abstract and reading list follow below. Abstract: Software-Defined Internet Exchange Points (SDXes) promise to significantly increase the flexibility and function of interdomain traffic delivery on the Internet. Unfortunately, current SDX designs cannot yet achieve the scale required for large Internet exchange points (IXPs), which can host hundreds of participants exchanging traffic for hundreds of thousands of prefixes. Existing platforms are indeed too slow and inefficient to operate at this scale, typically requiring minutes to compile policies and millions of forwarding rules in the data plane. We motivate, design, and implement iSDX, the first SDX architecture that can operate at the scale of the largest IXPs. We show that iSDX reduces both policy compilation time and forwarding table size by two orders of magnitude compared to current state-of-the-art SDX controllers. Our evaluation against a trace from one of the largest IXPs in the world found that iSDX can compile a realistic set of policies for 500 IXP participants in less than three seconds. Our public release of iSDX, complete with tutorials and documentation, is already spurring early adoption in operational networks. Reading List: 1. K. Agarwal, C. Dixon, E. Rozner, and J. Carter. Shadow macs: Scalable label-switching for commodity ethernet. In Proceedings of the Third Workshop on Hot Topics in Software Defined Networking, HotSDN ’14, pages 157–162, New York, NY, USA, 2014. ACM. 2. J. Bailey, D. Pemberton, A. Linton, C. Pelsser, and R. Bush. Enforcing RPKI-based routing policy on the data plane at an internet exchange. August 2014. 3. J. Bailey, D. Pemberton, A. Linton, C. Pelsser, and R. Bush. Enforcing rpki-based routing policy on the data plane at an internet exchange. In Proceedings of the Third Workshop on Hot Topics in Software Defined Networking, HotSDN ’14, pages 211–212, New York, NY, USA, 2014. ACM. 4. V. Boteanu, H. Bagheri, and M. Pels. Minimizing arp traffic in the ams-ix switching platform using openflow. 2013. 5. M. Canini, P. Kuznetsov, D. Levin, and S. Schmid. A Distributed and Robust SDN Control Plane for Transactional Network Updates. In INFOCOM, 2015. 6. M. Casado, T. Koponen, S. Shenker, and A. Tootoonchian. Fabric: A retrospective on evolving sdn. In Proceedings of the First Workshop on Hot Topics in Software Defined Networks, HotSDN ’12, pages 85–90, New York, NY, USA, 2012. ACM. 7. B. S. Davie and Y. Rekhter. MPLS: technology and applications. San Francisco, 2000. 8. A. Dixit, F. Hao, S. Mukherjee, T. Lakshman, and R. Kompella. Towards an elastic distributed sdn controller. In Proceedings of the Second ACM SIGCOMM Workshop on Hot Topics in Software Defined Networking, HotSDN ’13, pages 7–12, New York, NY, USA, 2013. ACM, ACM. 9. D. Farinacci, V. Fuller, D. Meyer, and D. Lewis. The locator/id separation protocol (lisp). Internet Requests for Comments, January 2013. http://www . rfc-editor.org/rfc/rfc6830.txt 10. S. Hassas Yeganeh and Y. Ganjali. Kandoo: A framework for efficient and scalable offloading of control applications. In Proceedings of the First Workshop on Hot Topics in Software Defined Networks, HotSDN ’12, pages 19–24, New York, NY, USA, 2012. ACM, ACM. 11. N. Katta, O. Alipourfard, J. Rexford, and D. Walker. In- finite cacheflow in software-defined networks. In Proceedings of the Third Workshop on Hot Topics in Software Defined Networking, HotSDN ’14, pages 175–180, New York, NY, USA, 2014. ACM, ACM. 12. N. Katta, H. Zhang, M. Freedman, and J. Rexford. Ravana: Controller fault-tolerance in software-defined networking. In Proceedings of the 1st ACM SIGCOMM Symposium on Software Defined Networking Research, SOSR ’15, pages 4:1–4:12, New York, NY, USA, 2015. ACM. 13. T. Koponen, M. Casado, N. Gude, J. Stribling, L. Poutievski, M. Zhu, R. Ramanathan, Y. Iwata, H. Inoue, T. Hama, and S. Shenker. Onix: A distributed control platform for large-scale production networks. In Proceedings of the 9th USENIX Conference on Operating Systems Design and Implementation, OSDI’10, pages 1–6, Berkeley, CA, USA, 2010. USENIX Association. 14. V. Kotronis, X. Dimitropoulos, R. Kloti, B. Ager, P. Geor- ¨ gopoulos, and S. Schmid. Control exchange points: Providing qos-enabled end-to-end services via sdn-based interdomain routing orchestration. 2014. 15. C. Monsanto, J. Reich, N. Foster, J. Rexford, and D. Walker. Composing software-defined networks. In Proceedings of the 10th USENIX Conference on Networked Systems Design and Implementation, nsdi’13, pages 1–14, Berkeley, CA, USA, 2013. USENIX Association. 16. P. Richter, G. Smaragdakis, A. Feldmann, N. Chatzis, J. Boettger, and W. Willinger. Peering at peerings: On the role of ixp route servers. In Proceedings of the 2014 Conference on Internet Measurement Conference, IMC ’14, pages 31–44, New York, NY, USA, 2014. ACM. 17. N. Sarrar, S. Uhlig, A. Feldmann, R. Sherwood, and X. Huang. Leveraging zipf’s law for traffic offloading. ACM SIGCOMM Computer Communication Review, 42(1):16–22, January 2012. 18. S. Smolka, S. Eliopoulos, N. Foster, and A. Guha. A Fast Compiler for NetKAT. In ICFP, 2015. 19. J. Stringer, D. Pemberton, Q. Fu, C. Lorier, R. Nelson, J. Bailey, C. Correa, and C. Esteve Rothenberg. Cardigan: Sdn distributed routing fabric going live at an internet exchange. In Computers and Communication (ISCC), 2014 IEEE Symposium on, pages 1–7. IEEE, June 2014. 20. A.-W. Tam, K. Xi, and H. Chao. Use of devolved controllers in data center networks. In Computer Communications Workshops (INFOCOM WKSHPS), 2011 IEEE Conference on, pages 596–601. IEEE, April 2011. 21. A. Tootoonchian and Y. Ganjali. Hyperflow: A distributed control plane for openflow. In Proceedings of the 2010 Internet Network Management Conference on Research on Enterprise Networking, INM/WREN’10, pages 3–3, Berkeley, CA, USA, 2010. USENIX Association, USENIX Association. 22. S. Whyte. Project CARDIGAN An SDN Controlled Exchange Fabric. https://www.nanog . org/meetings/nanog57/presentations/ Wednesday/wed.lightning3.whyte.sdn. controlled.exchange.fabric.pdf, 2012. 23. Workshop on Prototyping and Deploying Experimental Software Defined Exchanges. https: // www.nitrd.gov/nitrdgroups/images/4/ 4d/SDX_Workshop_Proceedings.pdf. 24. M. Yu, J. Rexford, M. J. Freedman, and J. Wang. Scalable flow-based networking with Difane. SIGCOMM Computer Communication Review, 40(4):351–362, August 2010.

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QCB 302 Symposium Announcement
by Scott Karlin 17 Dec '15

17 Dec '15

Dear members of the Princeton biology community: As the culmination of QCB 302 we will hold a symposium for the students to present their work to the greater Princeton community. The symposium will feature talks from 8 exceptional undergraduates about their own original research in quantitative and computational biology in labs across campus. You are invited to join us on January 7th from 10AM to 1PM in CIL 280 to support these students and celebrate their hard work and accomplishments. I hope to see you there, Amanda Amodeo <aamodeo(a)princeton.edu> For details and the list of talks, visit: https://icahnthinkanddrink.princeton.edu/qcb-302-symposium-jan-7-10am/

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Colloquium Speaker: Lester Mackey Monday Dec 14, 12:30pm
by Nicole E. Wagenblast 14 Dec '15

14 Dec '15

Colloquium Speaker- Joint talk with CSML Lester Mackey, Stanford University Monday, December 14, 12:30pm Computer Science 105 Matrix Completion and Matrix Concentration The goal in matrix completion is to recover a matrix from a small subset of noisy entries. Web-scale instances of this problem include collaborative filtering for recommendation and link prediction in social networks. Many modern matrix completion algorithms provide strong recovery guarantees but scale poorly due to the repeated and costly computation of truncated SVDs. To address this deficiency, in the first part of this talk, I will introduce Divide-Factor-Combine (DFC), a parallel divide-and-conquer framework for boosting the scalability of a matrix completion algorithm while retaining its theoretical guarantees. Our experiments demonstrate the near-linear to super-linear speed-ups attainable with this approach, and our analysis shows that DFC enjoys high-probability recovery guarantees comparable to those of its base algorithm. Fundamental to our analysis – and to the analyses of many matrix completion procedures – are matrix concentration inequalities that characterize the fluctuations of a random matrix about its mean. In the second part of this talk, I will show how Stein’s method of exchangeable pairs can be used to derive concentration inequalities for matrix-valued random elements. When applied to a sum of independent random matrices, this approach yields matrix generalizations of the classical inequalities due to Hoeffding, Bernstein, Khintchine, and Rosenthal. The same technique delivers bounds for sums of dependent random matrices and more general matrix functionals of dependent random elements.

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ACM/IEEE celebrates Computer Science Education week- Speaker: Robert Sedgewick
by Nicole E. Wagenblast 10 Dec '15

10 Dec '15

All ACM / IEEE-CS meetings are open to the public. Students and their parents are welcome. There is no admission charge. Princeton ACM/IEEE- CS Chapters The following "computer science in education" talk is part of our celebration of Computer Science Education Week (December 7 -13, http://csedweek.org ). Computer Science for the Masses Robert Sedgewick, Princeton University, Computer Science Thursday, December 10, 8pm Friend Center, 101 Colleges and universities need a good "introduction to computer science" for their students. What should we teach and how should we teach it? How should we use technology in an introductory course? This talk describes a introductory computer science course at Princeton University. The course has been under development for 25 years. It is the highest-enrolled course at Princeton, attracting two-thirds of all students, preparing them all for further study in computer science (nearly 40% of all Princeton students are taking a CS course at any point in time). The content is broad and deep, building on a solid foundation in programming to address fundamental issues in theoretical computer science and to also provide an overview of computer architecture, all in the context of interesting applications in science, engineering, and commerce. The course is currently using a new textbook, extensive online content, and studio-produced lecture videos. Robert Sedgewick is the founding chair and the William O. Baker Professor in the Department of Computer Science at Princeton and a member of the board of directors of Adobe Systems. His research interests revolve around algorithm design, including mathematical techniques for the analysis of algorithms. Prof. Sedgwick is the author of the very popular textbook "Algorithms, Fourth Edition" and other books on algorithms that have been best-sellers for decades. On-line meeting notice: http://PrincetonACM.acm.org/meetings/mtg1512.pdf

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