{"id":1293,"date":"2016-08-29T11:56:07","date_gmt":"2016-08-29T11:56:07","guid":{"rendered":"https:\/\/prismacloud.eu\/?p=1293"},"modified":"2017-05-22T14:09:40","modified_gmt":"2017-05-22T14:09:40","slug":"1293-2","status":"publish","type":"post","link":"https:\/\/prismacloud.eu\/1293-2\/","title":{"rendered":"Practical Signing-Right Revocation"},"content":{"rendered":"<p style=\"text-align: justify;\"><strong>Authors<\/strong><\/p>\n<p style=\"text-align: justify;\">Michael Till Beck (Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen),\u00a0Stephan Krenn (AIT Austrian Institute of Technology),\u00a0Franz-Stefan Preiss (IBM Reserach Zurich),\u00a0Kai Samelin (IBM Research Zurich and Technische Universit\u00e4t Darmstadt)<\/p>\n<p style=\"text-align: justify;\"><strong>Abstract<\/strong><\/p>\n<p style=\"text-align: justify;\">One of the key features that must be supported by every\u00a0modern PKI is an efficient way to determine (at verification) whether the\u00a0signing key had been revoked. In most solutions, the verifier periodically\u00a0contacts the certificate authority (CA) to obtain a list of blacklisted, or\u00a0whitelisted, certificates. In the worst case this has to be done for every\u00a0signature verification. Besides the computational costs of verification,\u00a0after revocation all signatures under the revoked key become invalid.\u00a0In the solution by Boneh et al. at USENIX \u201901, the CA holds a share\u00a0of the private signing key and contributes to the signature generation.\u00a0After revocation, the CA simply denies its participation in the interactive\u00a0signing protocol. Thus, the revoked user can no longer generate valid\u00a0signatures. We extend this solution to also cover privacy, non-trusted\u00a0setups, and time-stamps. We give a formal definitional framework, and\u00a0provide elegantly simple, yet provably secure, instantiations from efficient\u00a0standard building blocks such as digital signatures, commitments, and\u00a0partially blind signatures. Finally, we propose extensions to our scheme.<\/p>\n<p style=\"text-align: justify;\"><strong>Venue<\/strong><\/p>\n<p style=\"text-align: justify;\">9th International Conference of Trust and Trustworthy Computing, TRUST 2016 (http:\/\/trust2016.sba-research.org\/)<\/p>\n<p style=\"text-align: justify;\"><strong>Place and Date<\/strong><\/p>\n<p style=\"text-align: justify;\">Vienna, Austria, 29-30 August 2016<\/p>\n<p style=\"text-align: justify;\"><strong>Publication Reference<\/strong><\/p>\n<p style=\"text-align: justify;\">Michael Till Beck, Stephan Krenn, Franz-Stefan Preiss, and Kai Samelin. \u201cPractical Signing-Right Revocation\u201c, in: Michael Franz and Panos Papadimitratos (eds.) TRUST 2016, pp. 21-39, LNCS 9824, Vienna\/Austria, Springer.<\/p>\n<p style=\"text-align: justify;\">[<a href=\"https:\/\/prismacloud.eu\/wp-content\/uploads\/2016\/08\/Practical-Signing-Right-Revocation.pdf\">Download<\/a>]<\/p>\n<p><strong>Bibtex<\/strong><\/p>\n<pre><code>@inproceedings{fkmtz16,\r\n<\/code><code>Author \u00a0 \u00a0 = {Michael Till Beck and Stephan Krenn and Franz-Stefan Preiss and Kai Samelin},\r\n<\/code><code>Title \u00a0 \u00a0 = {{Practical Signing Right Revocation}},\r\n<\/code><code>Booktitle \u00a0= {TRUST 2016},\r\n<\/code><code>Publisher\u00a0 = {Springer},\r\n<\/code><code>editor \u00a0\u00a0\u00a0\u00a0= {M. Franz and P. Papadimitratos},<\/code> <code>year = {2016},<\/code> <code>series = {LNCS},<\/code> <code>volume = {9824},<\/code> <code>pages = {21--39}<\/code> <code>}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Michael Till Beck, Stephan Krenn, Franz-Stefan Preiss, and Kai Samelin. \u201cPractical Signing-Right Revocation\u201c, in: Michael Franz and Panos Papadimitratos (eds.) TRUST 2016, pp. 21-39, LNCS 9824, Vienna\/Austria, Springer.<\/p>\n","protected":false},"author":2,"featured_media":746,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,8],"tags":[],"_links":{"self":[{"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/posts\/1293"}],"collection":[{"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/comments?post=1293"}],"version-history":[{"count":6,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/posts\/1293\/revisions"}],"predecessor-version":[{"id":1935,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/posts\/1293\/revisions\/1935"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/media\/746"}],"wp:attachment":[{"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/media?parent=1293"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/categories?post=1293"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prismacloud.eu\/wp-json\/wp\/v2\/tags?post=1293"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}