@article {15115,
	title = {Two-server password-only authenticated key exchange},
	journal = {Journal of Computer and System Sciences},
	volume = {78},
	year = {2012},
	month = {2012/03//},
	pages = {651 - 669},
	abstract = {Typical protocols for password-based authentication assume a single server that stores all the information (e.g., the password) necessary to authenticate a user. An inherent limitation of this approach, assuming low-entropy passwords are used, is that the user's password is exposed if this server is ever compromised. To address this issue, it has been suggested to share a user's password information among multiple servers, and to have these servers cooperate (possibly in a threshold manner) when the user wants to authenticate. We show here a two-server version of the password-only key-exchange protocol of Katz, Ostrovsky, and Yung (the KOY protocol). Our work gives the first secure two-server protocol for the password-only setting (in which the user need remember only a password, and not the servers' public keys), and is the first two-server protocol (in any setting) with a proof of security in the standard model. Our work thus fills a gap left by the work of MacKenzie et al. (2006) [31] and Di Raimondo and Gennaro (2006) [16]. As an additional benefit of our work, we show modifications that improve the efficiency of the original KOY protocol.},
	keywords = {Key-exchange protocols, passwords},
	isbn = {0022-0000},
	doi = {10.1016/j.jcss.2011.09.005},
	url = {http://www.sciencedirect.com/science/article/pii/S0022000011001048},
	author = {Katz, Jonathan and MacKenzie,Philip and Taban,Gelareh and Gligor,Virgil}
}
