<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">REMINDER: </font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class=""><br class=""></font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">Department of Mathematics & Computer Science</font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">Combinatorics & Theory Seminar</font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class=""><br class=""></font></b></div><div class=""><span data-sheets-value="{"1":2,"2":"NON-STANDARD DAY"}" data-sheets-userformat="{"2":15339,"3":{"1":0},"4":[null,2,16777215],"6":{"1":[{"1":2,"2":0,"5":[null,2,0]},{"1":0,"2":0,"3":3},{"1":1,"2":0,"4":1}]},"8":{"1":[{"1":2,"2":0,"5":[null,2,0]},{"1":0,"2":0,"3":3},{"1":1,"2":0,"4":1}]},"9":1,"10":2,"11":4,"12":0,"14":[null,2,16711680],"15":"Bree Serif","16":14}" style="color: rgb(255, 0, 0); text-align: center;" class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">NON-STANDARD DAY</font></b></span></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">Thursday, October 3, 2019</font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">Crerar 390 @ 3:30 pm</font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class=""><br class=""></font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">Yevgeniy Dodis</font></b></div><div class=""><b class=""><font face="TimesNewRomanPSMT" size="4" class="">NYU</font></b></div><div class=""><div class=""><b class=""><a href="http://cs.nyu.edu/~dodis" class=""><font face="TimesNewRomanPSMT" size="4" class="">http://cs.nyu.edu/~dodis</font></a></b></div><div class=""><b style="text-align: center;" class=""><font face="TimesNewRomanPSMT" size="4" class=""><br class=""></font></b></div><div class=""><font face="TimesNewRomanPSMT" size="4" class=""><b style="text-align: center;" class="">Title: “</b><b style="text-align: center;" class="">Seedless Fruit is the Sweetest: Random Number Generation, Revisited”</b></font></div><div class=""><p class="MsoNormal"><font face="TimesNewRomanPSMT" size="4" class=""><b class="">Abstract:<span style="color: rgb(33, 33, 33); background-color: white; background-position: initial initial; background-repeat: initial initial;" class=""> </span></b><span style="background-color: white;" class="">The need for high-quality randomness in cryptography makes random-number generation one of its most fundamental tasks.</span></font></p><p class="MsoNormal"><font face="TimesNewRomanPSMT" size="4" class=""> A recent important line of work (initiated by Dodis et al., CCS ’13) focuses on the notion of *robustness* for pseudorandom number generators (PRNGs) with inputs—these are primitives that use various sources to accumulate sufficient entropy into a state, from which pseudorandom bits are extracted. Robustness ensures that PRNGs remain secure even under state compromise and adversarial control of entropy sources. However, the achievability of robustness inherently depends on a *seed*, or alternatively, on an ideal primitive (e.g., a random oracle) independent of the source of entropy. Both assumptions are problematic: Seed generation requires randomness to start with, and it is arguable whether the seed or the primitive can be kept independent of the source.</font></p><p class="MsoNormal"><font face="TimesNewRomanPSMT" size="4" class=""><br class="">Our work resolves this dilemma by putting forward new notions of robustness which enable both (1) *seedless* PRNGs and (2) primitive-dependent adversarial sources of entropy. To bypass obvious impossibility results, we make a realistic compromise that the source produces sufficient entropy even given its evaluations of the underlying primitive. We also provide natural practical provably-secure constructions based on hash-function designs from compression functions, block ciphers, and permutations. <br class="">On the way, we consider both a *computational* variant of robustness, where attackers only make a bounded number of queries to the ideal primitive, as well as a new *information-theoretic* variant, which dispenses with this assumption to a certain extent, at the price of requiring a high rate of injected weak randomness (as it is, e.g., plausible on Intel’s on-chip RNG). The latter notion enables applications such as ever-lasting security.<br class="">Joint work with Sandro Coretti, Harish Karthikeyan, and Stefano Tessaro.<b class=""><o:p class=""></o:p></b></font></p><p class="MsoNormal" style="text-align: justify;"><font face="TimesNewRomanPSMT" size="4" class="">Host: Prof. David Cash</font></p><p class="MsoNormal" style="text-align: justify;"><br class=""></p></div></div><div class="">
<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><p class="MsoNormal" style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; font-size: 11px;"></p><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><div class=""><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;"><b class=""><font size="4" class="">Donna Brooms-Blue</font></b></p><br class="Apple-interchange-newline" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;"><span><span><img apple-inline="yes" id="9DD23DA2-CA50-4BCC-A96A-7CAAB2AF8B0B" src="cid:E864EB6F-E291-4290-A25E-EB2464E6444D" class=""></span><div style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><b style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><br class=""></b><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class="">Department Secretary</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class="">Computer Science Department</span></span></div><div style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">John Crerar Library Building<br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class="">5730 So. Ellis Ave.</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class="">Chicago, IL. 60637</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class="">(773) 702-6614 - Office</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class="">(773) 702-8487 - Fax</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal;" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; float: none; display: inline !important;" class=""><a href="mailto:donna@cs.uchicago.edu" class="">donna@cs.uchicago.edu</a></span></span></div>
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