{"title":"Yang等人基于密码的实用双服务器认证与密钥交换系统的安全性分析","authors":"X. Yi","doi":"10.1109/NSS.2010.97","DOIUrl":null,"url":null,"abstract":"Typical protocols for password-based authentication assumes a single server which stores all the passwords necessary to authenticate users. If the server is compromised, user passwords are disclosed. To address this issue, Yang et al. proposed a practical password-based two-server authentication and key exchange protocol, where a front-end server, keeping one share of a password, and a back-end server, holding another share of the password, cooperate in authenticating a user and, meanwhile, establishing a secret key with the user. In this paper, we present two ``half-online and half-offline'' attacks to Yang et al.'s protocol. By these attacks, user passwords can be determined once the back-end server is compromised. Therefore, Yang et al.'s protocol has no essential difference from a password-based single-server authentication protocol.","PeriodicalId":127173,"journal":{"name":"2010 Fourth International Conference on Network and System Security","volume":"182 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2010-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":"{\"title\":\"Security Analysis of Yang et al.'s Practical Password-Based Two-Server Authentication and Key Exchange System\",\"authors\":\"X. Yi\",\"doi\":\"10.1109/NSS.2010.97\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Typical protocols for password-based authentication assumes a single server which stores all the passwords necessary to authenticate users. If the server is compromised, user passwords are disclosed. To address this issue, Yang et al. proposed a practical password-based two-server authentication and key exchange protocol, where a front-end server, keeping one share of a password, and a back-end server, holding another share of the password, cooperate in authenticating a user and, meanwhile, establishing a secret key with the user. In this paper, we present two ``half-online and half-offline'' attacks to Yang et al.'s protocol. By these attacks, user passwords can be determined once the back-end server is compromised. Therefore, Yang et al.'s protocol has no essential difference from a password-based single-server authentication protocol.\",\"PeriodicalId\":127173,\"journal\":{\"name\":\"2010 Fourth International Conference on Network and System Security\",\"volume\":\"182 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2010-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"5\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"2010 Fourth International Conference on Network and System Security\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/NSS.2010.97\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"2010 Fourth International Conference on Network and System Security","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/NSS.2010.97","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Security Analysis of Yang et al.'s Practical Password-Based Two-Server Authentication and Key Exchange System
Typical protocols for password-based authentication assumes a single server which stores all the passwords necessary to authenticate users. If the server is compromised, user passwords are disclosed. To address this issue, Yang et al. proposed a practical password-based two-server authentication and key exchange protocol, where a front-end server, keeping one share of a password, and a back-end server, holding another share of the password, cooperate in authenticating a user and, meanwhile, establishing a secret key with the user. In this paper, we present two ``half-online and half-offline'' attacks to Yang et al.'s protocol. By these attacks, user passwords can be determined once the back-end server is compromised. Therefore, Yang et al.'s protocol has no essential difference from a password-based single-server authentication protocol.