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Tygar" /> <meta name="citation_author_institution" content="University of California at Berkeley" /> <meta name="citation_publication_date" content="1999" /> <meta name="citation_conference_title" content="8th USENIX Security Symposium (USENIX Security 99)" /> <meta name="citation_pdf_url" content="http://seclab.cs.ucdavis.edu/ ~bishop/scriv/1996-share86.pdf" />   <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"d823139095",applicationID:"509444"};;/*! 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class="element-invisible">You are here</h2><div class="breadcrumb"><a href="/">Home</a> 禄 <strong>Why Johnny Can't Encrypt: A Usability Evaluation of PGP 5.0</strong></div> <div id="share-social-links">  <div class="gplusone-container"> <div class="g-plusone" data-size="medium" data-align="right"></div>  <script type="text/javascript"> (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })(); </script> </div>  <a href="https://twitter.com/share" class="twitter-share-button" data-align="right">Tweet</a> <script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");</script>  <div id="fb-root"></div> <script>(function(d, s, id) { var js, fjs = d.getElementsByTagName(s)[0]; if (d.getElementById(id)) return; js = d.createElement(s); js.id = id; js.src = "//connect.facebook.net/en_US/all.js#xfbml=1"; fjs.parentNode.insertBefore(js, fjs); }(document, 'script', 'facebook-jssdk')); </script> <div class="fb-share-button" data-send="false" data-layout="button_count" data-width="90" data-show-faces="false"></div>  </div> </div> <div class='below-breadcrumb clearfix'></div> <div id="social-link-icons"> <h4 class="block-title clearfix">connect with us</h4> <div class="view view-conference-node-element-blocks view-id-conference_node_element_blocks view-display-id-block_2 view-dom-id-98b8f18e404a5d22b5473ccb09c5c9ce"> </div> </div> <h1 class='page-title '> Why Johnny Can't Encrypt: A Usability Evaluation of PGP 5.0 </h1> <div id='tabs'> <div class='page-tabs limiter clearfix'> </div> </div> <div class='content-wrapper clearfix'> <div class="region region-content"> <div class='block-system main block-page-content clearfix' id="block-system-main"> <div class="block-content clearfix"> <div id="node-155718" class="node node-paper paper-type-0 clearfix" id="node-155718"> <div class="content" class="node-content clearfix prose"> <div class="field field-name-field-paper-description field-type-text-long field-label-above"><div class="field-label">Abstract: </div><div class="field-items"><div class="field-item odd"><p><span style="font-family: verdana,arial,helvetica,sans-serif;">User errors cause or contribute to most computer security failures, yet user interfaces for security still tend to be clumsy, confusing, or near-nonexistent. Is this simply due to a failure to apply standard user interface design techniques to security?聽 We argue that, on the contrary, effective security requires a different usability standard, and that it will not be achieved through the user interface design techniques appropriate to other types of consumer software. </span></p><p><span style="font-family: verdana,arial,helvetica,sans-serif;">To test this hypothesis, we performed a case study of a security program which does have a good user interface by general standards:聽 PGP 5.0.聽 Our case study used a cognitive walkthrough analysis together with a laboratory user test to evaluate whether PGP 5.0 can be successfully used by cryptography novices to achieve effective electronic mail security.聽 The analysis found a number of user interface design flaws that may contribute to security failures, and the user test demonstrated that when our test participants were given 90 minutes in which to sign and encrypt a message using PGP 5.0, the majority of them were unable to do so successfully. </span></p><p><span style="font-family: verdana,arial,helvetica,sans-serif;">We conclude that PGP 5.0 is not usable enough to provide effective security for most computer users, despite its attractive graphical user interface, supporting our hypothesis that user interface design for effective security remains an open problem.聽 We close with a brief description of our continuing work on the development and application of user interface design principles and techniques for security. </span></p></div></div></div><div class="field field-name-field-paper-people field-type-node-reference field-label-hidden"><div class="field-items"><div class="field-item odd"> <div id="node-155716" class="node node-speaker clearfix" id="node-155716"> <h2 class="node-title clearfix"><a href="/conference/8th-usenix-security-symposium/speaker-or-organizer/alma-whitten-carnegie-mellon">Alma Whitten, Carnegie Mellon University</a></h2> <div class="content" class="node-content clearfix prose"> </div> </div> </div><div class="field-item even"> <div id="node-155717" class="node node-speaker clearfix" id="node-155717"> <h2 class="node-title clearfix"><a href="/conference/8th-usenix-security-symposium/speaker-or-organizer/j-d-tygar-university-california">J. D. Tygar, University of California at Berkeley</a></h2> <div class="content" class="node-content clearfix prose"> </div> </div> </div></div></div><div class="field field-name-field-bibtex-node field-type-node-reference field-label-hidden"><div class="field-items"><div class="field-item odd"><div class="bibtex-accordion"><div class="bibtex-accordion-label">BibTeX</div><div class="bibtex-accordion-content"><div class="bibtex-text-entry bibtex-accordion-text-entry">@inproceedings {271563,<br /> author = {Alma Whitten and J. D. Tygar},<br /> title = {Why Johnny Can{\textquoteright}t Encrypt: A Usability Evaluation of {PGP} 5.0},<br /> booktitle = {8th USENIX Security Symposium (USENIX Security 99)},<br /> year = {1999},<br /> address = {Washington, D.C.},<br /> url = {https://www.usenix.org/conference/8th-usenix-security-symposium/why-johnny-cant-encrypt-usability-evaluation-pgp-50},<br /> publisher = {USENIX Association},<br /> month = aug<br /> }<br /> </div><div class="bibtex-download-link bibtex-accordion-download-link"><a href="/biblio/export/bibtex/271563">Download</a></div></div></div></div></div></div><div class="group-legacy-file-links field-group-div"><h3><span>Links</span></h3><div class="field field-name-field-presentation-paper field-type-link-field field-label-inline clearfix"><div class="field-label">Paper: </div><div class="field-items"><div class="field-item odd"><a href="http://seclab.cs.ucdavis.edu/ ~bishop/scriv/1996-share86.pdf">http://seclab.cs.ucdavis.edu/ ~bishop/scriv/1996-share86.pdf</a></div></div></div><div class="field field-name-field-presentation-paper-html field-type-link-field field-label-inline clearfix"><div class="field-label">Paper (HTML): </div><div class="field-items"><div class="field-item odd"><a href="http://www.usenix.org/events/sec99/full_papers/whitten/whitten_html/index.html">http://www.usenix.org/events/sec99/full_papers/whitten/whitten_html/index.html</a></div></div></div></div> </div> <div class='node-links clearfix'><ul class="links inline"><li class="comment_forbidden first last"><span><a href="/user/login?destination=comment/reply/155718%23comment-form">Log in</a> or    <a href="/user/register?destination=comment/reply/155718%23comment-form">Register</a> to post comments</span></li> </ul></div> </div> </div> </div> </div> </div> </div> </div> </div> <div id="footer-outer"><div id='footer' class='limiter clearfix'> <div id='footer-region'> <div class="region region-footer"> <div class='block block-block 27 clearfix' id="block-block-27"> <div class="block-content clearfix prose"><div style="padding-top: .25em;"> <p style="color: inherit;">© USENIX <script>new Date().getFullYear()>document.write(new Date().getFullYear());</script></p> </div></div> </div> <div class='block block-menu menu-footer clearfix' id="block-menu-menu-footer"> <div class="block-content clearfix"><ul class="menu"><li class="first leaf"><a href="/privacy-policy">Privacy Policy</a></li> <li class="last leaf"><a href="/contact">Contact Us</a></li> </ul></div> </div> </div> </div> </div></div> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"d823139095","applicationID":"509444","transactionName":"YVJVZksCXkEEVhIMWFgYYkBQTBodDFsCAE8YR19C","queueTime":0,"applicationTime":359,"atts":"TRVWEAMYTU8=","errorBeacon":"bam.nr-data.net","agent":""}</script></body> </html>