Nevertheless, despite this progress, some basic and seemingly achievable security properties have eluded our reach. For example, we are unable to prove the security of basic tools for manipulating weak/leaky random sources, such as as pseudo-entropy generators and seed-dependent computational condensers. We also do not know how to prove leakage-resilient security of any cryptosystem whose secret key is uniquely determined by its public key. In the context of deterministic encryption we do not have a standard-model constructions achieving the strongest notion of security proposed by Bellare, Boldyreva and O'Neill (CRYPTO '07), that would allow us to encrypt arbitrarily correlated messages of sufficiently large individual entropy.
In this work, we provide broad black-box separation results, showing that the security of such primitives cannot be proven under virtually any standard cryptographic hardness assumption via a reduction that treats the adversary as a black box. We do so by formalizing the intuition that ``the only way that a reduction can simulate the correctly distributed view for an attacker is to know all the secrets, in which case it does not learn anything useful from the attack''. Such claims are often misleading and clever way of getting around them allow us to achieve a wealth of positive results with imperfect/leaky randomness. However, in this work we show that this intuition can be formalized and that it indeed presents a real barrier for the examples given above.Category / Keywords: foundations / Black-Box Reductions, Leakage, Deterministic Encryption Date: received 12 Aug 2012, last revised 14 Dec 2012 Contact author: wichs at cs nyu edu Available format(s): PDF | BibTeX Citation Note: This is the full version of a paper that appears at ITCS 2013. Version: 20121214:164012 (All versions of this report) Discussion forum: Show discussion | Start new discussion