<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><br class=""><div class=""><b class="" style="text-align: -webkit-auto; orphans: 2; widows: 2;"><font class=""><b class=""><font class="" size="4">Sean Hallgren</font></b></font></b><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class=""><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; text-align: -webkit-auto; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; text-align: -webkit-auto; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="margin: 0in 0in 0.0001pt;"><div class="" style="margin: 0in 0in 0.0001pt;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class=""><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div apple-content-edited="true" class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="margin: 0in 0in 0.0001pt;"><span class=""><font class="" size="4"><span class=""><i class="">Penn State University</i></span></font></span></div><div class="" style="margin: 0in 0in 0.0001pt;"><span class=""><font face="Cambria" size="4" class=""><b class=""><br class=""></b></font></span></div><div class="" style="margin: 0in 0in 0.0001pt;"><span class=""><span class=""><b class=""><font class="" size="4">Friday, December 6, 2019 at 3:00 pm</font></b></span></span></div><div class="" style="margin: 0in 0in 0.0001pt;"><b class=""><font class="" size="4">Crerar 390</font></b></div><div class="" style="margin: 0in 0in 0.0001pt;"><font size="4" class=""><span class=""><b class=""><br class=""></b></span><br class=""><font class=""><b class=""><font class="">Title:</font></b><span class=""> </span></font></font><font size="4" class=""><b class="">Quantum algorithms and post-quantum cryptography</b></font></div></div></div></div><font class=""><br class=""></font><div class=""><b class=""><font class="" size="4">Abstract:</font></b></div><div class=""><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;">Understanding the strengths and limitations of quantum computers is a fundamental problem. Finding quantum algorithms </span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;">that have exponential speedups over the best known classical algorithm is particularly interesting. So far examples of this</span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;"> </span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;">type have been mostly number theoretic in nature. As public-key cryptography is based on computationally hard problems in</span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;"> </span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;">number theory, developing post-quantum cryptography depends on understanding which problems have efficient quantum</span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;"> </span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;">algorithms. For example, our efficient quantum algorithm for computing the unit group was one of the ingredients for breaking</span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;"> </span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;">some systems that are based on finding short generators in ideal lattices. In this talk I will discuss my work in quantum</span><span class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); font-size: large; text-align: -webkit-auto;"> algorithms and its connections to post-quantum cryptography.</span></div><div class=""><span class=""><b class=""><i class=""><font class="" size="3"><br class=""></font></i></b></span></div><div class=""><span class=""><b class=""><i class=""><font class="" size="3">Bio:</font></i></b></span></div><div class=""><i class="" style="caret-color: rgb(33, 33, 33); color: rgb(33, 33, 33); text-align: -webkit-auto;"><font size="3" class="">Sean Hallgren is a Professor of Computer Science and Engineering at Penn State University. He is the recipient of a PECASE award from NSF and a Vannevar Bush Faculty Fellowship from DoD. Prior to joining Penn State he led the quantum computing group at NEC Laboratories. He has a Ph.D. in computer science from UC Berkeley.</font></i></div><div class=""><span class=""><font class=""><font class="" size="4"><b class=""><br class=""></b></font></font></span></div><div class=""><span class=""><font class=""><font class="" size="4"><b class="">Host: Fred Chong</b></font></font></span></div><div class=""><span class=""><font class=""><font class="" size="4"><b class=""><br class=""></b></font></font></span></div><div class=""><span class=""><font class=""><font class="" size="4"><b class="">PDF:</b></font></font></span></div><div class=""><span class=""><font class=""><font class="" size="4"><b class=""></b></font></font></span></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></body></html>