August 2021 - talks - lists.cs.princeton.edu

Khiem Ngo will present his FPO "TOLERATING SLOWDOWNS IN REPLICATED STATE MACHINES" on Wednesday, August 25, 2021 at 3PM via Zoom.
by jfarquer＠cs.princeton.edu 19 Aug '21

19 Aug '21

Khiem Ngo will present his FPO "TOLERATING SLOWDOWNS IN REPLICATED STATE MACHINES" on Wednesday, August 25, 2021 at 3PM via Zoom. Zoom link: https://princeton.zoom.us/j/97848004548 The members of Khiem's committee are as follows: Wyatt Lloyd (Adviser); Readers: Amit Levy and Siddhartha Sen (Microsoft Research); Examiners: Michael Freedman, Ravi Netravali, Wyatt Lloyd. A copy of his thesis is available upon request. Please email gradinfo(a)cs.princeton.edu <mailto:gradinfo@cs.princeton.edu> if you would like a copy of the thesis. All are welcome to attend his talk. Abstract follows below: Replicated state machines (RSMs) are linearizable, fault-tolerant groups of replicas that are coordinated using a consensus algorithm. RSMs are used throughout large-scale sys[1]tems, such as distributed databases, cloud storage, and service managers. At such scale, it is common for some machines to be slow. In this dissertation, we address the prob[1]lem of developing slowdown-tolerant RSMs that continue to operate as fast RSMs despite the presence of slow replicas. We define s-slowdown-tolerance and identify why existing consensus protocols are not slowdown-tolerant. As the first and pragmatic step toward slowdown-tolerant RSMs, we design, implement, and evaluate two 1-slowdown-tolerant consensus protocols, Copilot and Latent Copilot. Copilot replication is the first 1-slowdown-tolerant consensus protocol: it delivers normal latency despite the slowdown of any 1 replica. Copilot uses two distinguished replicas-the pilot and copilot-to proactively add redundancy to all stages of processing a client's command. Copilot uses dependencies and deduplication to resolve potentially differing orderings proposed by the pilots. To avoid dependencies leading to either pilot being able to slow down the group, Copilot uses fast takeovers that allow a fast pilot to complete the ongoing work of a slow pilot. Copilot includes two optimizations-ping[1]pong batching and null dependency elimination-that improve its performance when there are 0 and 1 slow pilots respectively. Our evaluation of Copilot shows its performance is lower but competitive with Multi-Paxos and EPaxos when no replicas are slow. When a replica is slow, Copilot is the only protocol that avoids high latencies. Latent Copilot, a variant of Copilot, is another design and implementation of a 1- slowdown-tolerant consensus protocol. Latent Copilot operates with one active pilot, which actively proposes commands, and one latent pilot, which proposes commands only when necessary. In this way, Latent Copilot achieves an intermediate tradeoff between Multi[1]Paxos and Copilot in terms of throughput and slowdown tolerance. Our evaluation of La[1]iii tent Copilot shows that it achieves 1-slowdown-tolerance and that its performance with no slowdowns is comparable to Multi-Paxos. Finally, we generalize the design of Copilot replication to handle more than one slow[1]down. We provide the design of an s-slowdown-tolerant protocol that achieves slowdown tolerance despite s slow replicas.

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Fermi Ma will present his FPO "Quantum Security and Fiat-Shamir for Cryptographic Protocols" on Tuesday, August 24, 2021 at 4pm via Zoom.
by jfarquer＠cs.princeton.edu 16 Aug '21

16 Aug '21

Fermi Ma will present his FPO "Quantum Security and Fiat-Shamir for Cryptographic Protocols" on Tuesday, August 24, 2021 at 4pm via Zoom. Zoom link: https://princeton.zoom.us/j/97642906902 The members of his committee are as follows: Mark Zhandry (Adviser); Readers: Zeev Dvir, Ran Raz; Examiners: Sanjeev Arora, Gillat Kol, and Mark Zhandry. A copy of his thesis is available upon request. Please email gradinfo(a)cs.princeton.edu <mailto:gradinfo@cs.princeton.edu> if you would like a copy of the thesis. Everyone is invited to attend his talk. Abstract: This talk will cover new results on the security of cryptographic protocols in the quantum setting and the Fiat-Shamir heuristic for removing interaction. (1) Quantum Rewinding. Many cryptosystems are proven secure by rewinding an interactive adversary to extract its responses across multiple invocations. Unfortunately, this technique only suffices for classical security, since recording the outputs of a quantum adversary may irreversibly damage its state. Obtaining a suitable quantum analogue of rewinding has been a long-standing open problem in post-quantum cryptography. In this talk, I will describe a general-purpose quantum rewinding procedure capable of extracting an unlimited number of responses from any quantum adversary; prior techniques were limited to a constant number. Our primary application is to prove that Kilian's succinct argument system for NP is post-quantum secure. (2) Quantum Secure Computation from One-Way Functions. Next, I will cover results on multi-party computation, a central primitive in cryptography that enables mutually distrusting parties to compute a shared function over their inputs while revealing no other information. We show that when all parties are quantum, secure multi-party computation can be based solely on the existence of the minimal cryptographic primitive: one-way functions. This is in stark contrast to the classical setting where such an implication is not known, and is considered unlikely. (3) The Security of Fiat-Shamir. The final part of this talk will cover the soundness of the Fiat-Shamir heuristic, a powerful technique that uses a cryptographic hash function to remove interaction from certain cryptographic protocols. We consider two popular applications of Fiat-Shamir: building non-interactive succinct arguments from Kilian's protocol and obtaining digital signatures from a wide range of identification protocols. We demonstrate significant barriers to soundly instantiating Fiat-Shamir for Kilian's succinct arguments using any concrete Fiat-Shamir hash function. We also raise the interesting possibility that natural identification protocols can be compiled with simple, non-cryptographic Fiat-Shamir hash functions.

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Friday, August 13, 2021 - Princeton Wireless Distinguished Seminar Series - Sumit Roy, University of Washington
by Emily C. Lawrence 06 Aug '21

06 Aug '21

ECE Princeton Wireless Distinguished Seminar Series Speaker: Sumit Roy, University of Washington Title: Future Vehicular Radars: Two Aspects Day: Friday, August 13, 2021 Time: 1:00 pm Room: Please register here: [ https://princeton.zoom.us/meeting/register/tJAvd-2rqjkuHdQcCp7MUlGrW7CSb3Th… | https://princeton.zoom.us/meeting/register/tJAvd-2rqjkuHdQcCp7MUlGrW7CSb3Th… ] Host: Yasaman Ghasempour Abstract: This talk will present an overview of recent research in FUNLAB around the use of vehicular radar for advanced driver assistance systems (en route to a future vision of autonomous driving). Wideband (typically FMCW or chirp) radars are being increasingly deployed onboard vehicles as key high-resolution sensor for environmental mapping/imaging and various safety features. The talk will focus on the evolving role of radar `cognition’ in complex operating environments to address two important future challenges: 1. Mitigating multi-access interference among Radars (e.g. dense traffic scenario) The talk will first illustrate the impact of mutual interference on detection performance in Chirp/FMCW radars and then highlight some multi-access protocol design approaches for effective resource sharing among multiple radars. 2. Contributions to radar vision via new radar hardware (MIMO radar) + associated advanced signal processing (Synthetic Aperture principles) as well as Convolutional Neural Network (`Radar Net’) based machine learning approach for enhanced object detection/classification in challenging circumstances. Bio: Sumit Roy received the B. Tech. degree from the Indian Institute of Technology (Kanpur) in 1983, and the M. S. and Ph. D. degrees from the University of California (Santa Barbara), all in Electrical Engineering in 1985 and 1988 respectively, as well as an M. A. in Statistics and Applied Probability in 1988. He is currently Professor, Electrical & Comp. Engineering, appointed to a term Distinguished Professorship for Integrated Systems (2014-19); since Sep. 2020, he serves as a rotator for US Dept. of Defense’s Program Lead for Innovate Beyond 5G https://5g-to-xg.org. His research interests include fundamental design and evaluation of wireless communication and sensor network systems spanning a diversity of technologies and application areas: next-gen (5G & beyond) wireless LANs and cellular networks, heterogeneous network coexistence, spectrum sharing, software defined radio platforms, vehicular and sensor networking. He spent 2001-03 on academic leave at Intel Wireless Technology Lab as a Senior Researcher engaged in systems architecture and standards development for ultra-wideband systems (Wireless PANs) and next generation high-speed wireless LANs. During Jan-July 2008, he was Science Foundation of Ireland’s E.T.S. Walton Awardee for a sabbatical at University College, Dublin and also recipient of a Royal Acad. Engineering (UK) Distinguished Visiting Fellowship during summer 2011. He has served as IEEE Communications Society (ComSoc) Distinguished Lecturer and as Associate Editor for all the major ComSoc journals. He served 2 terms as (elected) member of Executive Committee, National Spectrum Consortium dedicated to efficient spectrum sharing between Federal and commercial networks and is the co-author of IEEE TAES 2016 Best paper award for work on Radar-Comm coexistence. He was elevated to IEEE Fellow by Communications Society in 2007 for ``contributions to multi-user communications theory and cross-layer design of wireless networking standards”.

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