2009/06/25 by Łukasz Chmielewski, Chmielewski, Łukasz, Jaap-Henk Hoepman +3
Computer Science · #Advanced Authentication Protocols Security #Cryptography and Data Security #Cryptography and Security (cs.CR) #FOS: Computer and information sciences #User Authentication and Security Systems #cs.CR
paper · pdf · doi:10.48550/arxiv.0906.4668
arxiv created 2009/06/25 · openalex publication_date 2009/06/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
Human memory is not perfect - people constantly memorize new facts and forget old ones. One example is forgetting a password, a common problem raised at IT help desks. We present several protocols that allow a user to automatically recover a password from a server using partial knowledge of the password. These protocols can be easily adapted to the personal entropy setting, where a user can recover a password only if he can answer a large enough subset of personal questions. We introduce client-server password recovery methods, in which the recovery data are stored at the server, and the recovery procedures are integrated into the login procedures. These methods apply to two of the most common types of password based authentication systems. The security of these solutions is significantly better than the security of presently proposed password recovery schemes. Our protocols are based on a variation of threshold encryption that may be of independent interest.