{"id":497,"date":"2012-06-12T18:51:22","date_gmt":"2012-06-13T00:51:22","guid":{"rendered":"http:\/\/www.comm.utoronto.ca\/dkundur\/?page_id=497"},"modified":"2013-04-06T23:21:18","modified_gmt":"2013-04-07T05:21:18","slug":"physical-layer-security","status":"publish","type":"page","link":"https:\/\/www.comm.utoronto.ca\/dkundur\/research\/physical-layer-security\/","title":{"rendered":"Physical Layer Security"},"content":{"rendered":"<table class=\"alignright\" width=\"250\" border=\"0\" cellspacing=\"0\" cellpadding=\"5\">\n<tbody>\n<tr>\n<td>\n<h4>Other Research Areas<\/h4>\n<p><a style=\"display:none;\" id=\"ddetlink2125344613\" href=\"javascript:expand(document.getElementById('ddet2125344613'))\">Expand List<\/a>\n<div class=\"ddet_div\" id=\"ddet2125344613\"><script language=\"JavaScript\" type=\"text\/javascript\">expand(document.getElementById('ddet2125344613'));expand(document.getElementById('ddetlink2125344613'))<\/script><\/p>\n<ul>\n<li><a href=\"\/dkundur\/smart-grid\">Smart Grid<\/a><\/li>\n<li><a href=\"\/dkundur\/cyber-physical-systems\/\">Cyber-Physical Systems<\/a><\/li>\n<li><a href=\"\/dkundur\/multimedia-and-sensor-networks\/\">Multimedia &amp; Sensor Networks<\/a><\/li>\n<li><a href=\"\/dkundur\/dynamical-systems\/\">Dynamical Systems<\/a><\/li>\n<li><a href=\"\/dkundur\/digital-forensics\/\">Digital Forensics<\/a><\/li>\n<li><a href=\"\/dkundur\/physical-layer-security\/\">Physical Layer Security<\/a><\/li>\n<li><a href=\"\/dkundur\/multimedia-security-and-drm\/\">Multimedia Security<\/a><\/li>\n<li><a href=\"\/dkundur\/blind-image-restoration\/\">Blind Image Restoration<\/a><\/li>\n<li><a href=\"\/dkundur\/image-fusion\/\">Image Fusion<\/a><\/li>\n<\/ul>\n<p><\/div><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h1>Physical Layer Security for Distributed Enciphering<\/h1>\n<p style=\"text-align: left;\"><img decoding=\"async\" class=\"lazyload attachment-80x60 alignleft\" title=\"Physical Layer Security\" src=\"data:image\/svg+xml,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20width%3D%27200%27%20height%3D%27200%27%20viewBox%3D%270%200%20200%20200%27%3E%3Crect%20width%3D%27200%27%20height%3D%27200%27%20fill-opacity%3D%220%22%2F%3E%3C%2Fsvg%3E\" data-orig-src=\"\/dkundur\/wp-content\/uploads\/PhysicalLayerSecurity.png\" alt=\"Physical Layer Security\" width=\"200\" height=\"200\" \/><\/p>\n<p>Physical layer security has recently gained attention as an alternative approach to control information access beyond traditional cryptographic mechanisms. Essentially, the approach which is typically keyless, exploits the interference within the communication system that occurs at the physical layer. This is done through the use of coding whereby the codes attempt to maximize the capacity between a legitimate sender and receiver in the communication system while minimizing the capacity between a legitimate sender and eavesdropper. They keyless property makes this approach to security attractive for applications such as distributed computing and sensor networks. Typically such nodes are autonomous and deployed in hostile environments such that node capture can reveal critical keying information used in traditional cryptography to jeopardize network security.<\/p>\n<p>Our research focuses on problems related to secret sharing, distributed enciphering and distributed source coding for confidentiality and compression at the physical layer. Our algorithms are inspired with sensor networks in mind.<\/p>\n<p>The basic setup through-out the research assumes that\u00a0a set of sensor nodes encipher their data without collaboration and\u00a0without any prior shared secret materials. The challenge is dealt by an\u00a0eavesdropper who intercepts a subset of the enciphered data and wishes\u00a0to gain knowledge of the uncoded data. We study this problem using information theoretic models\u00a0to gain insight and an intuitive understanding of the\u00a0characteristics of this system problem. There are four main parts to this body of work:<\/p>\n<ol>\n<li>\u00a0The first part deals with noiseless channels whereby the goal is for\u00a0sensor nodes to simultaneously source code and encipher their data. Inner and outer regions of the associated capacity region (i.e the set of all\u00a0source coding and equivocation rates) for this problem under general\u00a0distortion constraints are derived. The main conclusion is that\u00a0unconditional secrecy is unachievable unless the distortion is maximal,\u00a0rendering the data useless.<\/li>\n<li>The second component provides a\u00a0practical coding scheme based on distributed source coding using\u00a0syndromes (DISCUS) that provides secrecy beyond the equivocation\u00a0measure, i.e. secrecy on each symbol in the message.<\/li>\n<li>The third part\u00a0involves discrete memoryless channels such that the goal is for sensor\u00a0nodes to both channel code and encipher their data. Inner and\u00a0outer regions to the secrecy capacity region, i.e. the set of all\u00a0channel coding rates that achieve (weak) unconditional secrecy are derived. The main\u00a0conclusionis that interference allows (weak) unconditional\u00a0secrecy to be achieved in contrast to the noiseless case in the first part of this work.<\/li>\n<li>The fourth part addresses wireless channels with fading\u00a0and additive Gaussian noise. A general outer region and an\u00a0inner region based on an equal SNR assumption is derived and it is shown that the two are\u00a0partially tight when the maximum available user powers are admissible.<\/li>\n<\/ol>\n<h5>Related Publications<\/h5>\n<div class=\"teachpress_pub_list\"><form name=\"tppublistform\" method=\"get\"><a name=\"tppubs\" id=\"tppubs\"><\/a><\/form><div class=\"teachpress_message_error\"><p>Sorry, no publications matched your criteria.<\/p><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Other Research Areas Expand List Smart Grid Cyber-Physical Systems Multimedia &#8230;<\/p>\n","protected":false},"author":1,"featured_media":1005,"parent":9,"menu_order":6,"comment_status":"open","ping_status":"open","template":"","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"class_list":["post-497","page","type-page","status-publish","has-post-thumbnail","hentry"],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/PfR3Ra-81","_links":{"self":[{"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/pages\/497","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/comments?post=497"}],"version-history":[{"count":19,"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/pages\/497\/revisions"}],"predecessor-version":[{"id":2545,"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/pages\/497\/revisions\/2545"}],"up":[{"embeddable":true,"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/pages\/9"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/media\/1005"}],"wp:attachment":[{"href":"https:\/\/www.comm.utoronto.ca\/dkundur\/wp-json\/wp\/v2\/media?parent=497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}