State recovery attacks comprise an important class of attacks on pseudorandom generators. In this paper we analyze resistance of pseudorandom generators against these attacks in terms of concrete security. We show that security of the Blum- Micali pseudorandom generator against state recovery attacks is tightly related to the security of the corresponding one-way function. C. Wolf, S. Lucks, P.-W. Yau (Eds.): WEWoRC 2005, LNI P-74, pp. 53-63, 2005. c Gesellschaft für Informatik e.V.