Theory
https://csd.cmu.edu/
enComputer Science Thesis Oral
https://csd.cmu.edu/calendar/thesis-oral-WILLIAMS-2024-05-02
<span>Computer Science Thesis Oral</span>
Reddy Conference Room, Gates Hillman 4405 and Zoom
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-05-02T15:00:00-04:00" title="Thursday, May 2, 2024 - 15:00">Thu, 05/02/2024 - 15:00</time>
</span>
In Person and Virtual - ET
Setup Times in Multiserver Systems
JALANI K. WILLIAMS
<p>In many systems, servers do not turn on instantly; instead, a setup time must pass before a server can begin work. These “setup times” can wreak havoc on a system's queueing; this is especially true in modern systems, where servers are regularly turned on and off as a way to reduce operating costs (energy, labor, CO2, etc.). To design modern systems which are both efficient and performant, we need to understand how setup times affect queues. </p><p>Unfortunately, despite successes in understanding setup in the single server setting, setup in the multiserver setting remains poorly understood. To circumvent the main difficulty in analyzing multiserver setup, all existing results assume that setup times are memoryless, i.e. distributed Exponentially. However, in most practical settings, setup times are close to Deterministic, and the widely used Exponential-setup assumption leads to unrealistic model behavior and a dramatic underestimation of the true harm caused by setup times. </p><p>This thesis represents a comprehensive characterization of the average waiting time in a multiserver system with Deterministic setup times, the M/M/k/Setup-Deterministic. In particular, we derive multiplicatively-tight lower and upper bounds on the average waiting time, demonstrating that setup times, along with their distributions, can not be ignored; setup times can cause profound increases in waiting time, especially when the distribution of setup time has low variability. Our bounds are the first closed-form bounds on waiting time in any finite-server system with setup times, including the extensively-studied Exponential setup system. Furthermore, we use our bounds to derive a highly-accurate approximation, which we evaluate in a variety of settings. These results are made possible via our new method for bounding the expectation of a random time integral, called the Method of Intervening Stopping Times or MIST. </p><p><strong>Thesis Committee:</strong></p><p>Weina Wang (Chair)<br>Mor Harchol-Balter<br>Alan Scheller-Wolf<br>Jamol Pender (Cornell University)<br>Bill Massey (Princeton University)</p><p><em>In Person and </em><a href="https://cmu.zoom.us/j/97486384732?pwd=Uk13dzhIY1VIclFwam95Tko2R3pkQT09" target="_blank"><em>Zoom</em></a><em> Participation. See announcement.</em></p>
<time datetime="2024-05-02T19:00:00Z">May 2, 2024 3:00pm</time>
<time datetime="2024-05-02T21:00:00Z">May 2, 2024 5:00pm</time>
https://jalaniw.github.io/
Ph.D. Candidate, Computer Science Department, Carnegie Mellon University
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Thesis Oral
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Reddy Conference Room, Gates Hillman 4405 and Zoom
Thu, 02 May 2024 19:00:00 +0000Anonymous222334971 at https://csd.cmu.eduComputer Science Thesis Oral
https://csd.cmu.edu/calendar/thesis-oral-FLANIGAN-2024-04-30
<span>Computer Science Thesis Oral</span>
Reddy Conference Room, Gates Hillman 4405 and Zoom
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-30T13:30:00-04:00" title="Tuesday, April 30, 2024 - 13:30">Tue, 04/30/2024 - 13:30</time>
</span>
In Person and Virtual - ET
Strengthening our Participatory Democracy Toolkit using Algorithms, Social Choice, and Social Science
BAILEY FLANIGAN
<p>In most of the world's democracies, policy decisions are primarily made by elected political officials. However, under mounting dissatisfaction with representative government due to issues ranging from social inequality to public distrust, a new proposal is taking off: to augment representative democracy with mechanisms by which the public can <em>directly participate in policymaking</em>. </p><p>The guiding application of this thesis will be one particular model of participation, <em>deliberative minipublics</em> (DMs), though we will argue that our contributions may apply to many models of direct participation. In a DM, a panel of citizens is selected by lottery from the population; then, this panel convenes around a particular policy issue to study background information, deliberate amongst themselves, and then weigh in on the issue. DMs have been gaining momentum over the past decade, and they are now being used at national and supranational levels, and integrated into representative governments.</p><p>Motivated by this application domain, we make the following main contributions: In <strong>Part I</strong>, we design algorithms for performing the random selection of DM participants, a process known as <em>sortition</em>. Our sortition algorithms permit users to make optimal trade-offs between descriptive representation and other desirable properties conferred by randomness, and we characterize these tradeoffs using game theory, optimization, and empirics. In <strong>Part II</strong>, we use a novel social choice theory framework to investigate a notion of representation that departs from descriptive representation in a key way: it accounts for the political reality that people may be affected to <em>widely varying degrees</em> by any given policy decision. In <strong>Part III</strong>, we study a key potential impact of the background information/deliberation phase of a DM: increases in the extent to which participants consider <em>how others in their society may be affected</em> by different policy options. In <strong>Part IV</strong>, we discuss why our contributions can be useful regardless of how DMs ultimately fare in the political sphere, and we highlight how the enclosed research illustrates new ways to combine tools from political science and computer science. </p><p><strong>Thesis Committee</strong></p><p>Ariel Procaccia (Chair) (Carnegie Mellon University / Harvard University)<br>Nihar Shah<br>Anupam Gupta (New York University)<br>Nika Haghtalab (University of California, Berkeley)<br>Ashish Goel (Stanford University)</p><p><em>In Person and </em><a href="https://cmu.zoom.us/j/2671719231" target="_blank"><em>Zoom</em></a><em> Participation. See announcement.</em></p>
<time datetime="2024-04-30T17:30:00Z">April 30, 2024 1:30pm</time>
<time datetime="2024-04-30T19:30:00Z">April 30, 2024 3:30pm</time>
https://sites.google.com/andrew.cmu.edu/baileyflanigan/home
Ph.D. Candidate, Computer Science Department, Carnegie Mellon University
Thesis Oral
<a href="https://csd.cmu.edu/people/doctoral-student/bailey-flanigan" hreflang="en">Bailey Flanigan</a>
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Reddy Conference Room, Gates Hillman 4405 and ZOom
Tue, 30 Apr 2024 17:30:00 +0000Anonymous222334927 at https://csd.cmu.eduComputer Science Thesis Proposal
https://csd.cmu.edu/calendar/thesis-proposal-PRASAD-2024-04-26
<span>Computer Science Thesis Proposal</span>
Gordon Bell Conference Room, Gates Hillman 5117
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-26T10:00:00-04:00" title="Friday, April 26, 2024 - 10:00">Fri, 04/26/2024 - 10:00</time>
</span>
In Person
Mechanism Design and Integer Programming in the Data Age
SIDDHARTH PRASAD
<p>Modern-day human-scale marketplaces such as recommender systems, advertisement markets, matching platforms, supply chain industries, electronic commerce platforms, and others must reckon with a balancing act of (i) understanding and respecting the incentives of the system's participants, (ii) obtaining optimal outcomes subject to those incentives, and (iii) ensuring that data is used in a sound manner to improve overall efficiency. The area of mechanism design from economics provides a rich language and toolkit to understand incentives and integer programming is an expressive optimization language that is the workhorse behind most practical solutions to real-world discrete optimization problems. This thesis studies how data-driven decisions can be integrated into fundamental algorithms from both areas to improve performance (economic, memory, run-time, etc.). </p><p>Within mechanism design, I focus on the design of revenue optimal mechanisms from a data-driven lens. I design algorithms, model new learning paradigms, and invent new mechanism classes for a variety of settings including two-part tariffs, combinatorial auctions, shrinking markets, and general multi-dimensional mechanism design. A highlight here is the first general tunable framework for integrating side information into mechanisms to boost revenue while preserving welfare and incentives. Within integer programming, I develop principled new methods for cutting plane configuration, which is one of the most important components in state-of-the-art branch-and-cut solvers. I develop a comprehensive generalization theory for cut selection that (i) unveils new geometric and combinatorial structure in the branch-and-cut algorithm and the class of Gomory cuts, (ii) improves and subsumes prior work via an abstract model of the underlying tree search, and (iii) is validated through experiments that demonstrate the impact of data-dependent parameter tuning. I also derive a new method of sequence-independent lifting for cutting planes that I validate through rigorous theory—by deriving broad conditions under which the new cuts define facets of the integer polytope—and extensive experiments. </p><p>I conclude with avenues for future work; most notably my preliminary ideas on combinatorial auctions with side information which calls for a blend of innovations in auction design and integer programming techniques. </p><p><strong>Thesis Committee:</strong></p><p>Maria-Florina Balcan (Co-chair)<br>Tuomas Sandholm (Co-chair)<br>Gérard Cornuéjols<br>Craig Boutilier (Google Research)<br>Peter Cramton (University of Maryland)</p><p><a href="https://sid-prasad.github.io/files/thesis_proposal.pdf" target="_blank">Additional Information</a></p>
<time datetime="2024-04-26T14:00:00Z">April 26, 2024 10:00am</time>
<time datetime="2024-04-26T14:00:00Z">April 26, 2024 10:00am</time>
https://sid-prasad.github.io/
Ph.D. Student, Computer Science Department, Carnegie Mellon University
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Thesis Proposal
<a href="https://csd.cmu.edu/people/doctoral-student/siddharth-prasad" hreflang="en">Siddharth Prasad</a>
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Gordon Bell Conference Room, Gates Hillman 5117
Fri, 26 Apr 2024 14:00:00 +0000Anonymous222334877 at https://csd.cmu.eduAlgorithms, Combinatorics and Optimization Seminar
https://csd.cmu.edu/calendar/seminar-series-ACO-2024-04-25
<span>Algorithms, Combinatorics and Optimization Seminar</span>
Wean Hall 8220
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-25T15:00:00-04:00" title="Thursday, April 25, 2024 - 15:00">Thu, 04/25/2024 - 15:00</time>
</span>
In Person
Perfect matchings in the random bipartite geometric graph
XAVIER PÉREZ GIMÉNEZ
<p>We consider the standard random bipartite geometric graph process in which n red vertices and n blue vertices are placed at random on the unit d-dimensional cube and edges are added sequentially, between vertices of different colors, in increasing order of edge-length. A natural question is to ask whether the first edge in the process that results in the minimum degree being at least one coincides, with high probability, with the first edge that creates a perfect matching. While this was already known to be false when d=2, as the thresholds are not even of the same order, we are able to positively answer it for dimension d at least 3. </p><p><em>This is joint work with Abigail Raz. </em></p><p><em>Tea and cookies at 4pm in the Math Lounge, Wean 6220 (bring your own cup if possible)</em></p>
<time datetime="2024-04-25T19:00:00Z">April 25, 2024 3:00pm</time>
<time datetime="2024-04-25T20:00:00Z">April 25, 2024 4:00pm</time>
https://math.unl.edu/xperezgimenez2
Associate Professor, Department of Mathematics, University of Nebraska-Lincoln
https://aco.math.cmu.edu/abs-23-24/apr25.html
<a href="mailto:alanlew@andrew.cmu.edu">alanlew@andrew.cmu.edu</a>
Seminar Series
<a href="https://csd.cmu.edu/research/research-areas/algorithms-and-complexity" hreflang="en">Algorithms and Complexity</a>
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Wean Hall 8220
Thu, 25 Apr 2024 19:00:00 +0000Anonymous222334912 at https://csd.cmu.eduJoint Theory Seminar / Computer Science Speaking Skills Talk
https://csd.cmu.edu/calendar/speaking-skills-WHITEHOUSE-2024-04-24
<span>Joint Theory Seminar / Computer Science Speaking Skills Talk</span>
Gates Hillman 8102
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-24T14:00:00-04:00" title="Wednesday, April 24, 2024 - 14:00">Wed, 04/24/2024 - 14:00</time>
</span>
In Person
Brownian Noise Reduction: Maximizing Privacy Subject to Accuracy Constraints
JUSTIN WHITEHOUSE
<p>There is a disconnect between how researchers and practitioners handle privacy-utility tradeoffs. Researchers primarily operate from a privacy-first perspective, setting strict privacy requirements and minimizing risk subject to these constraints. Practitioners often desire an accuracy-first perspective, possibly satisfied with the greatest privacy they can get subject to obtaining sufficiently small error. Ligett, et al. have introduced a “noise reduction” algorithm to address the latter perspective. </p><p>The authors show that by adding correlated Laplace noise and progressively reducing it on demand, it is possible to produce a sequence of increasingly accurate estimates of a private parameter while only paying a privacy cost for the least noisy iterate released. In this work, we generalize noise reduction to the setting of Gaussian noise, introducing the Brownian mechanism. The Brownian mechanism works by first adding Gaussian noise of high variance corresponding to the final point of a simulated Brownian motion. Then, at the practitioner's discretion, noise is gradually decreased by tracing back along the Brownian path to an earlier time.</p><p>Our mechanism is more naturally applicable to the common setting of <em><font>ℓ</font></em><sub>2</sub>-sensitivity, empirically outperforms existing work on common statistical tasks, and provides customizable control of privacy loss over the entire interaction with the practitioner. Overall, our results demonstrate that one can meet utility constraints while still maintaining strong levels of privacy.</p><p><em>Presented as part of the </em><a href="https://www.cs.cmu.edu/~theorylunch/" target="_blank"><em>Theory Lunch Seminar</em></a><em>. </em></p><p><em>Presented in Partial Fulfillment of the CSD Speaking Skills Requirement</em></p>
<time datetime="2024-04-24T18:00:00Z">April 24, 2024 2:00pm</time>
<time datetime="2024-04-24T19:00:00Z">April 24, 2024 3:00pm</time>
https://jwhitehouse11.github.io/
Ph.D Student, Computer Science Department, Carnegie Mellon University
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Speaking Skills
<a href="https://csd.cmu.edu/people/doctoral-student/justin-whitehouse" hreflang="en">Justin Whitehouse</a>
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Gates Hillman 8102
Wed, 24 Apr 2024 18:00:00 +0000Anonymous222334910 at https://csd.cmu.eduTheory Lunch Seminar
https://csd.cmu.edu/calendar/seminar-series-THEORY-LUNCH-2024-04-24
<span>Theory Lunch Seminar</span>
Gates Hillman 8102
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-24T12:00:00-04:00" title="Wednesday, April 24, 2024 - 12:00">Wed, 04/24/2024 - 12:00</time>
</span>
In Person
Metric Clustering and MST with Strong and Weak Distance Oracles
CHEN WANG
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<p>I will discuss recent results of k-clustering and MST in a new weak-strong oracle model. In this model, for a fixed metric space $(\chi, d)$, we can compute distances in two ways: via a "strong" oracle that returns exact distances $d(x,y)$, and a "weak" oracle that returns distances $ \tilde{d}(x,y)$ which may be arbitrarily corrupted with some probability. This model captures the increasingly common trade-off between employing both an expensive similarity model (e.g. a large-scale embedding model) and a less accurate but cheaper model. Hence, the goal is to make as few queries to the strong oracle as possible. We consider both "point queries", where the strong oracle is queried on a set of points $ S \subset \chi$ and returns $d(x,y)$ for all $x,y \in S$, and "edge queries" where it is queried for individual distances $d(x,y)$.
Our main contributions are optimal algorithms and lower bounds for clustering and Minimum Spanning Tree (MST) in this model. For $k$-centers, $k$-median, and $k$-means, we give constant factor approximation algorithms with only $ \tilde{\ O}(k)$ strong oracle point queries, and prove that $ \Omega{(k)}$ queries are required for any bounded approximation. For edge queries, our upper and lower bounds are both $ \tilde{\Theta}(k^2)$. Surprisingly, for the MST problem, we give an $ \ O{(\sqrt{ \log n})}$ approximation algorithm using no strong oracle queries at all, and we prove a matching $ \Omega{(\sqrt{ \log n})}$ lower bound which holds even if $ \tilde{\Omega}(n)$ strong oracle point queries are allowed.</p><p><em>Based on the </em><a href="https://arxiv.org/abs/2310.15863" target="_blank"><em>this paper</em></a></p>
<time datetime="2024-04-24T16:00:00Z">April 24, 2024 12:00pm</time>
<time datetime="2024-04-24T17:00:00Z">April 24, 2024 1:00pm</time>
https://sites.google.com/view/chen-wang/home
Postdoctoral Researcher, Texas A&M University and Rice University
https://www.cs.cmu.edu/~theorylunch/
<a href="mailto:mpittu@andrew.cmu.edu">mpittu@andrew.cmu.edu</a>
Seminar Series
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Gates Hillman 8102
Wed, 24 Apr 2024 16:00:00 +0000Anonymous222334932 at https://csd.cmu.eduComputer Science Thesis Proposal
https://csd.cmu.edu/calendar/thesis-oral-RAIZES-2024-04-22
<span>Computer Science Thesis Proposal</span>
Reddy Conference Room, Gates Hillman 4405 and Zoom
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-22T13:00:00-04:00" title="Monday, April 22, 2024 - 13:00">Mon, 04/22/2024 - 13:00</time>
</span>
In Person and Virtual - ET
Certified Deniability in a Quantum World
JUSTIN RAIZES
<p>Certified deletion is an influential paradigm that allows a user to delegate sensitive information to another user, and later verify that this information has been destroyed. Since its proposal by Broadbent and Islam (TCC '20), certified deletion has been extended to a wide variety of primitives, such as fully-homomorphic ciphertexts, encryption secret keys, signatures, and even programs.</p><p>However, current definitions of certified deletion do not capture all of the advantages of deletion. For example, in revocable signatures, an adversary who deletes a signature on a message <em>m </em>cannot output a valid signature for <em>m</em>, but may still be able to prove that it <em>used to possess one</em>. In other words, it proves that m was signed at some point.</p><p>The missing security property is the notion of deniability. Similarly to how Pass (CRYPTO '03) views deniability as a fundamental property of zero-knowledge, I view deniability as a fundamental property of certified deletion. Unfortunately, classical solutions for non-interactive deniability either lack public verifiability or reveal even more sensitive information in the future, contrary to the goals of certified deletion.</p><p>I propose to study how certified deletion can be strengthened to provide novel <em>deniability</em> guarantees for a wide variety of primitives, which I call <em>certified deniability</em>. These primitives include signatures, non-interactive zero-knowledge, and key leasing. Notably, the problem of deniable key leasing does not seem to have a classical counterpart to date. If time permits, I plan to extend these results to the related setting of unclonability under the name <em>single-copy explainability</em>, which guarantees that an adversary cannot turn one copy of some sensitive information into two copies that can both be explained - the validity of the other can be denied.</p><p><strong>Thesis Committee:</strong></p><p>Vipul Goyal (Chair) (Carnegie Mellon University / NTT Research)<br>Aayush Jain<br>Elaine Shi<br>Giulio Malavolta (Bocconi University / Max Planck Institute for Security and Privacy)</p><p><em>In Person and </em><a href="https://cmu.zoom.us/j/97866320651?pwd=QzFDbjg4UURLcDE0dEtGRlRmVkdEUT09" target="_blank"><em>Zoom</em></a><em> Participation. See announcement.</em></p>
<time datetime="2024-04-22T17:00:00Z">April 22, 2024 1:00pm</time>
<time datetime="2024-04-22T18:30:00Z">April 22, 2024 2:30pm</time>
https://sites.google.com/view/justinraizes/
Ph.D. Student, Computer Science Department, Carnegie Mellon University
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Thesis Proposal
<a href="https://csd.cmu.edu/people/doctoral-student/justin-raizes" hreflang="en">Justin Raizes</a>
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Reddy Conference Room, Gates Hillman 4405 and Zoom
Mon, 22 Apr 2024 17:00:00 +0000Anonymous222334876 at https://csd.cmu.eduJoint Theory Lunch Seminar / Computer Science Speaking Skills Talk
https://csd.cmu.edu/calendar/speaking-skills-KOTHAPALLI-2024-04-17
<span>Joint Theory Lunch Seminar / Computer Science Speaking Skills Talk</span>
Gates Hillman 8102
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-17T12:00:00-04:00" title="Wednesday, April 17, 2024 - 12:00">Wed, 04/17/2024 - 12:00</time>
</span>
In Person
Nova: Recursive Zero-Knowledge Arguments from Folding Schemes
ABHIRAM KOTHAPALLI
<p>Zero-knowledge proofs are a powerful cryptographic technique for demonstrating the correctness of computations without revealing any secret inputs. Modern applications are beginning to employ recursive zero-knowledge proofs (proofs that demonstrate the existence of other proofs) due to their distinct ability to prove stateful computations with dynamic control flow. </p><p>For instance, one can prove large statements such as “the current state of the blockchain is valid” by proving that “there exists a proof for the previous state of the blockchain and the most recent update is valid”. Recursive proofs can similarly be utilized to incrementally prove the correct execution of delay functions, virtual machines, transparency dictionaries, and distributed computations. </p><p><em>Presented as part of the </em><a href="https://www.cs.cmu.edu/~theorylunch/" target="_blank"><em>Theory Lunch Seminar</em></a><em> </em></p><p><em>Presented in Partial Fulfillment of the CSD Speaking Skills Requirement</em></p>
<time datetime="2024-04-17T16:00:00Z">April 17, 2024 12:00pm</time>
<time datetime="2024-04-17T17:00:00Z">April 17, 2024 1:00pm</time>
https://abhiramkothapalli.github.io/
Ph.D. Student, Computer Science Department, Carnegie Mellon University
https://www.cs.cmu.edu/~theorylunch/
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Speaking Skills
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Gates Hillman 8102
Wed, 17 Apr 2024 16:00:00 +0000Anonymous222334844 at https://csd.cmu.eduComputer Science Thesis Oral
https://csd.cmu.edu/calendar/thesis-oral-WU-2024-04-15
<span>Computer Science Thesis Oral</span>
Reddy Conference Room, Gates Hillman 4405
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-15T12:00:00-04:00" title="Monday, April 15, 2024 - 12:00">Mon, 04/15/2024 - 12:00</time>
</span>
In Person
What Can Cryptography Do For Transaction Fee Mechanism Design?
KE WU
<p>Recent works of Roughgarden (<em>EC’21</em>) and Chung and Shi (<em>SODA’23</em>) initiate the study of a new decentralized mechanism design problem called transaction fee mechanism design (TFM). Unfortunately, Chung and Shi showed two impossibility results that rule out the existence of dream TFMs. First, any TFM that provides incentive compatibility for individual users and miner-user coalitions must always have zero miner revenue, even for infinite block size. Second, assuming a finite block size, no non-trivial TFM can simultaneously provide incentive compatibility for any individual user and for any miner-user coalition.</p><p>This thesis explores potential relaxations and the theoretical landscape of transaction fee mechanisms under these relaxations in four key directions:</p><ol><li> <em>MPC-assisted model:</em> We introduce a new model, where the TFM is implemented through a joint multi-party computation (MPC) protocol among miners. While this model does not eliminate the zero-miner revenue limitation, it helps to overcome some impossibility results in the original model (henceforth called the <em><font>plain model</font></em>), leading to non-trivial mechanisms with incentive compatible guarantees. </li><li><em>Approximate Incentive Compatibility:</em> Allowing strategic players to gain no more than<em> ε</em>-additional utility compared to honest behavior, we design mechanisms with positive miner revenues in both the plain and MPC-assisted models. Despite achieving optimality with respect to the miner revenue, these mechanisms have poorly scalable miner revenue, as we proved with certain impossibility results.</li><li><em>Reasonable-world assumption:</em> We show that if we make a mildly stronger assumption assuming that we know a lower bound <em>h</em> on the number of honest users and an upper bound <em>d</em> on the number of bids controlled by the coalition, we can circumvent the previous limitations on miner revenue, and design mechanisms that generate optimal miner revenue linear in <em>h</em>.</li><li><em>Miner-user coalition proof: </em>Here, we consider another flavor of notion capturing incentives of the miner-user coalitions: miner-user coalition proof, which requires that any miner-user coalition is unstable. We show that we are able to design interesting transaction fee mechanisms for finite block sizes that satisfy incentive compatibility for any individual user and any miner coalition, as well as miner-user coalition proofness.</li></ol><p><strong>Thesis Committee:</strong> </p><p>Elaine Shi (Chair)<br>Ryan O'Donnell<br>Aayush Jain<br>Tim Roughgarden (Columbia University / A16Z)</p>
<time datetime="2024-04-15T16:00:00Z">April 15, 2024 12:00pm</time>
<time datetime="2024-04-15T18:00:00Z">April 15, 2024 2:00pm</time>
https://kewucs.com/
Ph.D. Candidate, Computer Science Department, Carnegie Mellon University
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Thesis Oral
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Reddy Conference Room, Gates Hillman 4405
Mon, 15 Apr 2024 16:00:00 +0000Anonymous222334815 at https://csd.cmu.eduComputer Science Speaking Skills Talk
https://csd.cmu.edu/calendar/speaking-skills-KACHAM-2024-04-11
<span>Computer Science Speaking Skills Talk</span>
Gates Hillman 7501
<span><span>Anonymous (not verified)</span></span>
<span><time datetime="2024-04-11T14:00:00-04:00" title="Thursday, April 11, 2024 - 14:00">Thu, 04/11/2024 - 14:00</time>
</span>
In Person
Fast streaming algorithms via a new Pseudorandom Generator
PRANEETH KACHAM
<p>In this talk, I'll present our work on a new pseudorandom generator (PRG) which can be considered a generalization of Nisan's PRG. </p><p>We show that the space-vs-time tradeoff presented by our Pseudorandom generator can be used to obtain streaming algorithms that are optimal in space while having a very small update time i.e., the time required for the streaming algorithm to process an update is very small. </p><p><em>Presented in Partial Fulfillment of the CSD Speaking Skills Requirement.</em></p>
<time datetime="2024-04-11T18:00:00Z">April 11, 2024 2:00pm</time>
<time datetime="2024-04-11T19:00:00Z">April 11, 2024 3:00pm</time>
https://www.praneethkacham.com/
Ph.D. Student, Computer Science Department, Carnegie Mellon University
<a href="mailto:matthewstewart@cmu.edu">matthewstewart@cmu.edu</a>
Speaking Skills
<a href="https://csd.cmu.edu/people/doctoral-student/praneeth-kacham" hreflang="en">Praneeth Kacham</a>
<a href="https://csd.cmu.edu/research/research-areas/theory" hreflang="en">Theory</a>
Gates Hillman 7501
Thu, 11 Apr 2024 18:00:00 +0000Anonymous222334559 at https://csd.cmu.edu