{"60217":{"#nid":"60217","#data":{"type":"event","title":"Dissertation Defense: Adam O\u0027Neill","body":[{"value":"\u003Cp\u003EAdam O\u0027Neill\u003C\/p\u003E\n\n\u003Cp\u003ESchool of Computer Science\u003C\/p\u003E\n\n\u003Cp\u003ECollege of Computing\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\n\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\n\n\n\n\u003Cp\u003EDate: Monday, August 9, 2010\u003C\/p\u003E\n\n\u003Cp\u003ETime: 1:00 pm - 3:00 pm EDT\u003C\/p\u003E\u003Cp\u003ELocation: TBD\u003C\/p\u003E\n\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\n\n\n\n\u003Ch4\u003ECommittee\u003C\/h4\u003E\u003Cul\u003E\u003Cli\u003EDr. Alexandra Boldyreva (Advisor, School of \nComputer\nScience)\u003C\/li\u003E\u003Cli\u003EDr. Mihir Bellare (Computer Science and Engineering, \nUniversity of\nCalifornia at San Diego)\u003C\/li\u003E\u003Cli\u003EDr. Richard Lipton (School of Computer \nScience)\u003C\/li\u003E\u003Cli\u003EDr.\nChris Peikert (School of Computer Science)\u003C\/li\u003E\u003Cli\u003EDr. Dana Randall \n(School of Computer\nScience)\u003C\/li\u003E\u003Cli\u003EDr. Patrick Traynor (School of Computer Science)\u003C\/li\u003E\u003C\/ul\u003E\n\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\n\n\n\n\n\n\u003Ch4\u003EAbstract\u003C\/h4\u003E\n\n\n\n\u003Cp\u003ETrapdoor functions, introduced in the seminal paper of\nDiffie and Hellman (IEEE Trans. Inf. Theory, 1976), are a fundamental \nnotion in\nmodern cryptography. \u0026nbsp;Informally,\ntrapdoor functions are easy to evaluate but hard to invert unless given \nan\nadditional input called the trapdoor.\u0026nbsp;\nSpecifically, the classical security notion considered for trapdoor\nfunctions is {\\em one-wayness}, which asks that it be hard to invert a\nuniformly random point in the range without the trapdoor.\u003C\/p\u003E\n\n\u003Cp\u003EMotivated by the demands of emerging applications of\ncryptography as well as stronger security properties desired from \nhigher-level\ncryptographic primitives constructed out of trapdoor functions, this \nthesis\nstudies new strengthenings to the notion of one-way trapdoor functions \nand\ntheir applications.\u0026nbsp; Our results are\norganized along two separate threads, wherein we introduce two new\ncryptographic primitives that strengthen the notion of one-wayness for \ntrapdoor\nfunctions in different ways:\u003C\/p\u003E\u003Cp\u003E*** Deterministic Encryption:\u0026nbsp; Our \nnotion of deterministic public-key\nencryption addresses the weaknesses of using trapdoor functions directly\n for\nencryption articulated by Goldwasser and Micali (J. Comput. Syst. Sci., \n1984)\nto the extent possible {\\em without} randomizing the encryption function\n(whereas Goldwasser and Micali address them using randomized \nencryption).\u0026nbsp; Specifically, deterministic encryption ensures\nno partial information is leaked about a high-entropy plaintext or even\nmultiple correlated such plaintexts.\u0026nbsp;\nDeterministic encryption has applications to fast search on encrypted\ndata, securing legacy protocols, and ``hedging\u0027\u0027 randomized encryption \nagainst\nbad randomness.\u0026nbsp; We show a secure construction\nof deterministic encryption in the random oracle model of Bellare and \nRogaway\n(CCS 1993) meeting our security notion for an unbounded number of \narbitrarily\ncorrelated plaintexts based on any randomized encryption scheme, as well\n as a\nmore efficient such construction based on RSA.\u0026nbsp;\nWe also show a secure construction of deterministic encryption without\nrandom oracles meeting our security notion for a {\\em bounded} number of\narbitrarily correlated plaintexts based on the notion of lossy trapdoor \nfunctions\nintroduced by Peikert and Waters (STOC 2008).\u003C\/p\u003E\u003Cp\u003E*** Adaptive \nTrapdoor Functions: Our notion of adaptive\ntrapdoor functions asks that one-wayness be preserved in the presence of\n an\ninversion oracle that can be queried on some range points.\u0026nbsp; The main \napplication we give is the\nconstruction of black-box chosen-ciphertext secure public-key encryption\n(meaning the code of the underlying primitive is not used in the \nconstruction\nbesides running it) from weaker general assumptions.\u0026nbsp; Namely, we show \nsuch a construction of\nchosen-ciphertext secure public-key encryption from adaptive trapdoor\nfunctions.\u0026nbsp; We then show that adaptive\ntrapdoor functions can be realized from lossy trapdoor functions \nintroduced by\nPeikert and Waters (STOC 2008) and from correlated-product secure \ntrapdoor\nfunctions introduced by Rosen and Segev (TCC 2009); in fact, we show \nadaptivity\nis strictly {\\em weaker} than the latter notions (in a black-box \nsense).\u0026nbsp; Notably, by slightly extending our framework\nand considering ``tag-based\u0027\u0027 adaptive trapdoor functions we obtain \nexactly the\nchosen-ciphertext secure encryption schemes proposed in the these works,\nthereby unifying them, although the schemes we obtain via adaptive \ntrapdoor\nfunctions are actually more efficient.\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Stronger Security Notions for Trapdoor Functions and Applications"}],"uid":"27174","created_gmt":"2010-07-26 14:47:38","changed_gmt":"2016-10-08 01:52:02","author":"Mike Terrazas","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2010-08-09T14:00:00-04:00","event_time_end":"2010-08-09T17:00:00-04:00","event_time_end_last":"2010-08-09T17:00:00-04:00","gmt_time_start":"2010-08-09 18:00:00","gmt_time_end":"2010-08-09 21:00:00","gmt_time_end_last":"2010-08-09 21:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"47223","name":"College of Computing"},{"id":"50875","name":"School of Computer Science"}],"categories":[],"keywords":[],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1791","name":"Student sponsored"}],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EFor more information, contact \u003Ca href=\u0022mailto:denton@cc.gatech.edu\u0022\u003EDani Denton\u003C\/a\u003E.\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}