Last week I attended the 44th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2017). The event was hosted at Paris 6 which is part of the Sorbonne, University of Paris. It was one of the best POPLs I can remember. The papers are both interesting and informative (you can read them all, for free, from the Open TOC), and the talks I attended were generally of very high quality. (Videos of the talks will be available soon—I will add links to this post.) Also, the attendance hit an all-time high: more than 720 people registered for POPL and/or one of its co-located events.
In this blog post I will highlight a few of my favorite papers at this POPL, as well as the co-located N40AI event, which celebrated 40 years of abstract interpretation. Disclaimer: I do not have time to describe all of the great stuff I saw, and I could only see a fraction of the whole event. So just because I don’t mention something here doesn’t mean it isn’t equally great.
While scientific papers were once available only to those willing to pay expensive fees to journal publishers, papers are now increasingly made available for free, as they enjoy some form of open access (OA). Not all forms of open access are the same, however. While the ACM SIGPLAN Executive Committee (of which I am the Chair) is generally happy with the OA rights SIGPLAN authors currently enjoy, it may be time to push for even stronger rights. Reasonable people may disagree about the costs and benefits of such rights. As such, we would like your feedback (even if you are not a SIGPLAN member).
Please consider filling out this open access survey. It should take 5-10 minutes.
The remainder of this blog post discusses the issues in more depth. We invite your feedback!
I just got back from CCS (ACM’s conference on Computer and Communications Security) in Vienna, Austria. I really enjoyed the conference and the city.
At the conference we presented our Build it, Break it, Fix it paper. In the same session was the presentation on a really interesting paper called Practical Detection of Entropy Loss in Pseudo-Random Number Generators, by Felix Dörre and Vladimir Klebanov. This paper presents a program analysis that aims to find entropy-compromising flaws in PRNG implementations; such flaws could make the PRNG’s outputs more predictable (“entropy” is basically a synonym for “uncertainty”). When a PRNG is used to generate secrets like encryption keys, less entropy means those secrets can be more easily guessed by an attacker.
A PRNG can be viewed as a deterministic function from an actually-random seed to a pseudo-random output. The key insight of the work is that this function should not “lose entropy” — i.e., its outputs should contain all of the randomness present in its seed. Another way of saying this is that the PRNG must be injective. The injectivity of a function can be checked by an automatic program analysis.
Using the tool they developed, the paper’s authors were able to find known bugs, and an important unknown bug in libgcrypt’s PRNG. Their approach was essentially a variation of prior work checking noninterference; I found the connection to this property surprising and insightful. As discussed in a prior post, security properties can often be challenging to state and verify; in this case the property is pleasingingly simple to state and practical to verify.
Both injectivity and noninterference are examples of K-safety properties, which involve relations between multiple (i.e., K) program executions. New technology to check such properties is being actively researched, e.g., in DARPA’s STAC program. This paper is another example of the utility of that general thrust of work, and of using programming languages techniques (automated program analysis) for proving security properties.
[This blog post was conceived by Steve Chong, at Harvard, and co-authored with Michael Hicks.]
Enforcing information security is increasingly important as more of our sensitive data is managed by computer systems. We would like our medical records, personal financial information, social network data, etc. to be “private,” which is to say we don’t want the wrong people looking at it. But while we might have an intuitive idea about who the “wrong people” are, if we are to build computer systems that enforce the confidentiality of our private information, we have to turn this intuition into an actionable policy.
Defining what exactly it means to “handle private information correctly” can be subtle and tricky. This is where programming language techniques can help us, by providing formal semantic models of computer systems within which we can define security policies for private information. That is, we can use formal semantics to precisely characterize what it means for a computer system to handle information in accordance with the security policies associated with sensitive information. Defining security policies is still a difficult task, but using formal semantics allows us to give security policies an unambiguous interpretation and to explicate the subtleties involved in “handling private information correctly.”
In this blog post, we’ll focus on the intuition behind some security policies for private information. We won’t dig deeply into formal semantics for policies, but we provide links to relevant technical papers at the end of the post. Later, we also briefly mention how PL techniques can help enforce policies of the sort we discuss here.
Peer review is at the heart of the scientific process. As I have written about before, scientific results are deemed publishable by top journals and conferences only once they are given a stamp of approval by a panel of expert reviewers (“peers”). These reviewers act as a critical quality control, rejecting bogus or uninteresting results.
But peer review involves human judgment and as such it is subject to bias. One source of bias is a scientific paper’s authorship: reviewers may judge the work of unknown or minority authors more negatively, or judge the work of famous authors more positively, independent of the merits of the work itself.
Double-blind: Authors are blind to their reviewers, who are blind to authors
The double-blind review process aims to mitigate authorship bias by withholding the identity of authors from reviewers. Unfortunately, simply removing author names from the paper (along with other straightforward prescriptions) may not be enough to prevent the reviewers from guessing who the authors are. If reviewers often guess and are correct, the benefits of blinding may not be worth the costs.
While I am a believer in double-blind reviewing, I have often wondered about its efficacy. So as part of the review process of CSF’16, I carried out an experiment: I asked reviewers to indicate, after reviewing a paper, whether they had a good guess about the authors of the paper, and if so to name the author(s). This post presents the results. In sum, reviewers often (2/3 of the time) had no good guess about authorship, but when they did, they were often correct (4/5 of the time). I think these results support using a double-blind process, as I discuss at the end.
Filed under Process, Science
Conferences are the heart of the PL research community. The best PL research is published at conferences, following a rigorous peer review process on par or better than the process of high-quality journals. Conferences are also where science gets done. As the respective community gathers to learn about the latest results, its members also network and interact, developing collaborations or carrying on projects that could produce the next breakthroughs. At conferences, students and young professors can rub elbows with luminaries, and researchers can develop problems and exchange ideas with practitioners.
Air travel warms the planet disproportionately
One drawback of conferences (compared to other forms of research publication) is their cost. The monetary cost is obvious: at least one of a paper’s authors must pay to attend the conference, a cost that includes registration, travel, and hotel. Another cost that is less often considered is the environmental cost. In particular, I’m thinking of the impact that travel to/from the conference has on global warming. Most conference attendees travel great distances, and so travel by airplane. But air travel is particularly bad for global warming. So I wondered: what is the cost of conference travel, in terms of carbon footprint?
To get some idea, I decided to estimate the carbon footprint of the PLDI’16 program committee (PC) meeting, held just before and at the same venue as POPL’16. The result directly sheds some light on the carbon footprint of in-person PC meetings, and by treating it as a sample of the PL community overall, sheds light on the carbon footprint of PL conferences. In this blog post I present the results of my analysis and conclude with thoughts about possible actions to mitigate environmental cost.
I recently read Martin Ford’s Rise of the Robots with the UMD CS faculty book club. The book considers the impact of the growth of information technology (IT) on the human labor market, and how the trend towards greater automation could eventually eliminate a substantial number of jobs. The result could be a radical, and disruptive, reshaping of the global economy.
I would recommend the book. I found it well-written and thought provoking. Ford capably argues from past economic and technology trends and also digs into particular problems, products, and research in order to extrapolate future impact. Of the ten faculty who discussed the book, nine of us (including me) were convinced that future automation will be increasingly disruptive to human labor markets.
While reading the book, I found myself wondering about my own role, and that of my field, in addressing this situation we’ve contributed to. Many computer scientists have high-minded ideals and wish to help society through IT innovation. What can we do to ensure that those ideals are realized, rather than perverted into the dystopian future that Ford is warning us about? Continue reading
The IEEE Cybersecurity Development (SecDev) Conference is a new conference focused on designing and building systems to be secure. It will be offered for the first time in Boston, MA, on November 3-4, 2016. This event was conceived, and is being organized, by Rob Cunningham; I’m pleased to be the PC Chair.
As stated in the call for papers, this first iteration of the conference is seeking short (5-page) papers, extended (1-page) abstracts, and tutorial proposals. The submission deadline is June 21, 2016 — if you have new results, old results you’d like to repackage, a tool, a process, a vision, or an idea you’d like to share with those working to make systems more secure, please consider submitting a paper!
This blog post explains why I think we need this conference, what I expect the first year to look like, and what sort of papers we hope to get, in question & answer format. Continue reading
[This guest post is by David Walker, a professor at Princeton, and recent winner of the SIGPLAN Robin Milner Young Researcher Award. –Mike]
Every once in a while it is useful to take a step back and consider where fruitful new research directions come from. One such place is from the confluence of two independent streams of thought. This is an idea that I picked up from George Varghese, who gave a wonderful talk on the topic at ACM SIGCOMM 2014 and summarized the ideas in a short paper for CCR. This blog post considers confluences in the context of programming languages research, reflects upon the role such confluences have played in my own research, and suggests some things we might learn from the process. My keynote talk from POPL 2016 touches on many of these same themes.
Matt at the White House, Jan 2015
This post is the second part of my March 10th interview of Matt Might, a PL researcher and Associate Professor in the Department of Computer Science at the University of Utah.
In Part I, we talked about Matt’s academic background, his PL research (including his favorite among the papers he’s written), and his work on understanding and treating rare disease, which began with the quest to diagnose his son Bertrand, and has led to a role in the President’s Initiative on Precision Medicine.
In this post, our conversation continues, covering the topics of blogging, privacy, managing a crazy schedule, and looking ahead to promising PL research directions. Continue reading