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<div style="color: rgb(0, 0, 0);"><span style="font-family: Helvetica; font-size: 12px;">This is an announcement of Alex Hoover's Dissertation Defense.</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
</span><span style="font-family: Helvetica; font-size: 12px;">===============================================</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
</span><span style="font-family: Helvetica; font-size: 12px;">Candidate: Alex Hoover</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Date: Monday, April 15, 2024</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Time: 10:30 am CT</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Remote Location: <a href="https://uchicago.zoom.us/j/4767905734?pwd=a3lZUXZiMHAzc29QYncvcWlSU01sUT09" id="OWAdefe9b61-20e8-1034-bd2b-76ad52634631" class="OWAAutoLink" style="text-align: left;">https://uchicago.zoom.us/j/4767905734?pwd=a3lZUXZiMHAzc29QYncvcWlSU01sUT09</a></span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Location: JCL 346</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Title: On the Limits of Efficiency and Privacy for Outsourced Computation</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Abstract: Private Information Retrieval (PIR) is a cryptographic primitive that allows a client to query for some element of a public database, held by a server, without revealing the element that
the client is interested in. Recent developments in PIR have used client-side preprocessing to speed up online query times. In this model, a client can run offline to compute a hint which it later uses to issue online queries. Unfortunately, all proposed solutions
in this model before this work suffer from two significant drawbacks: (1) updating an entry in the database requires some inefficient computation and (2) a client's query time is linear in their hint size.</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">In this work, we overcome both of these obstacles by proposing Plinko, a new PIR scheme in the client-side preprocessing model. As part of our construction, we provide a new primitive called an invertible
pseudorandom function, which allows someone with the secret key to find the pre-image of some output efficiently. This primitive allows us to generically upgrade two previously proposed schemes to both: (1) update entries with nearly-constant time and communication
and (2) avoid clients' linear pass through their hints, improving the asymptotic runtime for clients with large storage.</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">This talk focuses on the third and final chapter of my dissertation. However, I briefly discuss the how the other chapters in my dissertation contribute to the exploration of efficiency and privacy
in outsourced computation.</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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</span><span style="font-family: Helvetica; font-size: 12px;">Advisors: David Cash</span><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;"><br>
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Committee Members: David Cash, Aloni Cohen, and Raul Castro Fernandez</div>
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