Eyal, Gencer, Sirer and van Renesse hailed at Scaling Bitcoin 2015

Amidst raging debate between two competing proposals on how to extend Bitcoin to process more transactions per second, Cornell researchers Ittay Eyal, Adem Efe Gencer, Emin Gun Sirer, and Robbert van Renesse unveiled their proposal called Bitcoin-NG, Bitcoin Next Generation. Surprisingly, and in contrast with the current proposals, Bitcoin-NG improves both throughput and latency at the same time. CoinDesk described this announcement as "Perhaps the most newsworthy event of the day".


Date Posted: 10/06/2015

Paper by Leskovec-Chakrabarti-Kleinberg-Faloutsos wins Test of Time Award

The paper "Realistic, Mathematically Tractable Graph Generation and Evolution, Using Kronecker Multiplication" by Jure Leskovec, Deepayan Chakrabarti, Jon Kleinberg, and Christos Faloutsos has won the Test of Time Award from the 2015 ECML/PKDD conference.

The paper states, "How can we generate realistic graphs? In addition, how can we do so with a mathematically tractable model that makes it feasible to analyze their properties rigorously? Real graphs obey a long list of surprising properties: ... All published graph generators either fail to match several of the above properties, are very complicated to analyze mathematically... Here we propose ...  to use a non-standard matrix operation, the Kronecker product, to generate graphs that we refer to as “Kronecker graphs”. We show that Kronecker graphs naturally obey all the above properties."

(Aside: see Charlie Van Loan's J. Computational and Applied Math. paper "The ubiquitous Kronecker product" open archive)

ECML/PKDD is a federated conference that brings together the European Conference on Machine Learning with the conference on Principles and Practice of Knowledge Discovery in Databases.

The award is designed to recognize the impact over time of a paper that first appeared at the ECML/PKDD conference ten years earlier.

Date Posted: 10/06/2015

Big Red Hackathon draws 400 students from across the Northeast to Cornell Campus

The Big Red Hacks (BRH), a student-run 36-hour hackathon, drew around 400 students from the Northeast to Cornell’s campus. Teams of no more than four students have three days to create any type of computer application, while all work must to take place in the Physical Sciences Building. The event, now in its second, year was created by two CS undergraduates, Junia George and Leon Zaruvinsky, in an effort to bring the hackathon culture to Cornell. This year a BRH planning committee was formed with seven undergraduate students from various majors. The committee worked behind the scenes to develop the logo, schedule, website, as well as a registration site. The Computer Science Department (CS) at Cornell hosts this now annual event, which is made possible through the contributions of over ten industry sponsors and recruiters who participate at the event. 

Judges for the hackathon, which included both CS professors and corporate sponsors, judged the various teams on the following criteria: creativity, technical difficulty, aesthetics, potential, and demonstration. First place prize went to a Cornell team, Onyx, that developed a way to direct the user to multiple destinations without having to look at their phone by linking a smart watch to a smart phone. Second place went to DynaMap, an app that lets users choose from a host of country statistics, scraping the web and dynamically scaling the land area of different landmasses according to those statistics while preserving basic shape and relative location. Another mentionable team created Flushr, an app that allows you to view public restrooms in your area as well as see reviews on how others have rated them.

News coverage on the event:

Local Channel 8 from Syracuse news video about the event.

Cornell Daily Sun article.

Date Posted: 10/01/2015

Yoav Artzi wins best paper award at EMNLP 2015

Yoav Artzi, together with University of Washington coauthors Kenton Lee and Luke Zettlemoyer, has won one of two Best Paper Awards at the 2015 Conference on Empirical Methods in Natural Language Processing (EMNLP), one of the premier venues in NLP.

The paper, "Broad-coverage CCG Semantic Parsing with AMR", was selected from among 1300 submissions. It describes a grammar learning approach building Abstract Meaning Representations, a recently proposed, general formalism for representing core aspects of sentence meaning. This is significant step over previous CCG learning algorithms, both in scale and linguistic complexity. The paper will be presented at EMNLP 2015 in Lisbon, Portugal later this month.

Date Posted: 9/09/2015

Google research awards go to cloud-service security, probabilistic programming of SDNs, and privacy-preserving deep learning

Several exciting and wide-ranging projects at Cornell have won Faculty Research Awards from Google.

Vitaly Shmatikov (with Adam Smith of Penn State):  a system for privacy-preserving deep learning.  Deep learning based on artificial neural networks has led to dramatic improvements in speech and image recognition, language translation, and other AI tasks, yet centralized collection of training data from millions of users presents serious privacy risks.  This project aims to design and implement a practical system that will enable data holders to learn accurate neural-network models without sharing their training datasets but still benefitting from other participants who are concurrently learning similar models.

Nate Foster and Dexter Kozen: a new probabilistic framework for programming software-defined networks (SDNs). Most existing SDN languages are deterministic, which makes it difficult to give satisfactory treatments of phenomena such as congestion given uncertain traffic patterns or reliability in the presence of failures. This project will develop a new programming language based on probabilistic semantics and tools for compiling programs and automatically verifying formal properties.

Ari Juels and Tom Ristenpart: security property enforcement (SPE) for cloud services. SPE applies in settings in which a cloud provider such as Google wishes to apply proprietary algorithms to customers sensitive data. SPE provides strong evidence to  customers (or auditors working on their behalf) that the provider is not abusing its access to sensitive data and to the provider that malicious customers cannot exploit sensitive information about proprietary provider algorithms.

Rafael Pass: large-scale privacy-preserving computation. Cryptographic methods such as secure multi-party computation enable securely and privately performing any computation on individuals private inputs. Such methods, however, do not scale to the modern regime of large-scale distributed, parallel, data processing.  This project will develop methods to securely and privately process large amounts of data using parallel distributed algorithms.

Date Posted: 9/01/2015

The dark side of "smart contracts"

Ari Juels and Elaine Shi explain to MIT Technology Review that "smart contracts" could be problematic. Together with Ahmed Kosba of University of Maryland, the team, in the provocatively titled paper "The Ring of Gyges: Using smart contracts for crime", show that "criminal smart contracts" can  facilitate leakage of confidential information, theft of cryptographic keys, and various real-world "calling-card" crimes, such as murder, arson, and terrorism.

For example, a criminal organization might put out a smart contract on someone's life: an unpredictable feature of the crime-to-be, such as the time and location of the killing, is provided in a cryptographically sealed form in advance of the crime; the smart contract automatically releases the funds when this proof of responsiblity for the crime is opened by the criminals who perpetrated it.

“In some ways this is the perfect vehicle for criminal acts, because it’s meant to create trust in situations where otherwise it’s difficult to achieve,” says Juels.  “We are optimistic about [these contracts'] beneficial applications, but crime is something that is going to have to be dealt with in an effective way if those benefits are to bear fruit,” says Shi.

Date Posted: 8/28/2015

NSF award on cryptocurrencies in the news.

PIs Elaine Shi and Gün Sirer, with Berkeley PI Down Song, have received an NSF Large Collaborative grant on the science and applications of crypto-currency, leveraging cryptography, game theory, programming languages and systems security techniques to establish a rigorous scientific foundation for crypto-currencies and to build trustworthy infrastructure to enable their next generation applications. This work is key because crypto-currencies are a billion-dollar market, and hundreds of companies are entering this space, promising exciting new markets and eco-systems; but most crypto-currencies rely on heuristic designs without a solid appreciation of the necessary security properties, or any formal basis upon which strong assurance of such properties might be achieved.

Shi and Sirer have been quoted  about the grant in Bitcoin Magazine, Coindesk, and CoinTelegraph; the latter described the award as "probably the [NSF's] broadest effort in the Bitcoin space to date".

Co-PIs on the grant are Michael Hicks, David van Horn, and Jonathan Katz of UMD.

Date Posted: 8/24/2015

Cecil, clicks and Kleinberg in the New York Times

Using the explosion of interest in the story of Cecil the lion as a starting point, the New York Times recently explored the question of whether "online news has deteriorated, and that it is now focused on the viral at the expense of the substantive." While the founder of The Verge quipped that "Reading disposable web journalism is 'like eating a whole bag of Doritos'", Jon Kleinberg comments that these kinds of stories have probably always caught on, and what has changed now is just that the internet "makes visible and searchable what was once ephemeral".

Date Posted: 8/18/2015


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