{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T01:00:28Z","timestamp":1773622828904,"version":"3.50.1"},"reference-count":0,"publisher":"Walter de Gruyter GmbH","issue":"1","license":[{"start":{"date-parts":[[2013,11,9]],"date-time":"2013-11-09T00:00:00Z","timestamp":1383955200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"NSFC","doi-asserted-by":"crossref","award":["60973161"],"award-info":[{"award-number":["60973161"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"crossref","award":["ZYGX2010X015"],"award-info":[{"award-number":["ZYGX2010X015"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"crossref"}]},{"name":"National 973 Program of China","award":["2013CB834203"],"award-info":[{"award-number":["2013CB834203"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2014,2,1]]},"abstract":"Abstract.<\/jats:title>\n \n Asymmetric password based key exchange is a key exchange protocol\nwhere a client and a server share a low entropic password while the\nserver additionally owns a high entropic secret with respect to a public\nkey. There are simple solutions for this,\ne.g., [ACM Trans. Inf. Syst. Secur. 2 (1999), 230\u2013268]\nand its improvement in [Proceedings of CCS 1999, ACM (1999), 63\u201372].\nIn the present paper, we consider a new threat to this type of protocol: if\na server's high entropic secret gets compromised (e.g., due\nto cryptanalysis or a poor management), the adversary might\n quickly<\/jats:italic>\n break lots of passwords and cause uncountable damage.\nIn this case, one should not expect the protocol to be secure against\nan off-line dictionary attack since, otherwise, the protocol is\nin fact a secure password-only key exchange by making the server high entropic secret public.\nOf course a password-only key exchange does not suffer from this threat as the server does not have a high entropic secret at all. However, known password-only key exchange protocols are not very efficient (note: we only consider protocols without random oracles). This motivates us to study an efficient and secure asymmetric password key exchange that avoids the new threat.\nIn this paper, we first provide a formal model for the new threat, where essentially we require that the active adversary can break\n \n \n \n \u2113<\/m:mi>\n <\/m:math>\n $\\ell $<\/jats:tex-math>\n <\/jats:alternatives>\n <\/jats:inline-formula>\n passwords in\n \n \n \n \n \u03b1<\/m:mi>\n \u2113<\/m:mi>\n |<\/m:mo>\n \ud835\udc9f<\/m:mi>\n |<\/m:mo>\n <\/m:mrow>\n <\/m:math>\n $\\alpha \\ell |\\mathcal {D}|$<\/jats:tex-math>\n <\/jats:alternatives>\n <\/jats:inline-formula>\n steps (for\n \n \n \n \n \u03b1<\/m:mi>\n <<\/m:mo>\n 1<\/m:mn>\n \/<\/m:mo>\n 2<\/m:mn>\n <\/m:mrow>\n <\/m:math>\n $\\alpha &lt;1\/2$<\/jats:tex-math>\n <\/jats:alternatives>\n <\/jats:inline-formula>\n ) only with a probability negligibly close to\n \n \n \n \n exp<\/m:mo>\n (<\/m:mo>\n -<\/m:mo>\n \u03b2<\/m:mi>\n \u2113<\/m:mi>\n )<\/m:mo>\n <\/m:mrow>\n <\/m:math>\n $\\exp (-\\beta \\ell )$<\/jats:tex-math>\n <\/jats:alternatives>\n <\/jats:inline-formula>\n for some\n \n \n \n \n \u03b2<\/m:mi>\n ><\/m:mo>\n 0<\/m:mn>\n <\/m:mrow>\n <\/m:math>\n $\\beta &gt;0$<\/jats:tex-math>\n <\/jats:alternatives>\n <\/jats:inline-formula>\n , where\n \n \n \n \ud835\udc9f<\/m:mi>\n <\/m:math>\n $\\mathcal {D}$<\/jats:tex-math>\n <\/jats:alternatives>\n <\/jats:inline-formula>\n is a password dictionary. Then, we construct a framework of asymmetric password based key exchange.\nWe prove that our protocol is secure in the regular model where server high entropic key is never compromised and that it prevents the new threat. To do this, we introduce a new technique by\nabstracting a probabilistic experiment from the main proof and providing a neat analysis of it.\n <\/jats:p>","DOI":"10.1515\/jmc-2012-0010","type":"journal-article","created":{"date-parts":[[2013,11,11]],"date-time":"2013-11-11T15:14:10Z","timestamp":1384182850000},"page":"31-70","source":"Crossref","is-referenced-by-count":0,"title":["Persistent asymmetric password-based key exchange"],"prefix":"10.1515","volume":"8","author":[{"given":"Shaoquan","family":"Jiang","sequence":"first","affiliation":[{"name":"School of Computer Science and Engineering, University of Electronic Science and Technology of China; and Institute of Information Security, Mianyang Normal University, Mianyang 621000, P. R. China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"374","published-online":{"date-parts":[[2013,11,9]]},"container-title":["Journal of Mathematical Cryptology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/jmc-2012-0010\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/jmc-2012-0010\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T00:10:22Z","timestamp":1773619822000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/jmc-2012-0010\/html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,11,9]]},"references-count":0,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2013,11,9]]},"published-print":{"date-parts":[[2014,2,1]]}},"alternative-id":["10.1515\/jmc-2012-0010"],"URL":"https:\/\/doi.org\/10.1515\/jmc-2012-0010","relation":{},"ISSN":["1862-2984","1862-2976"],"issn-type":[{"value":"1862-2984","type":"electronic"},{"value":"1862-2976","type":"print"}],"subject":[],"published":{"date-parts":[[2013,11,9]]}}}