Exposure-Resilient Fun tions and All-Or-Nothing Transforms

New Dire tions in Design of Resilient Boolean Fun tions

Deterministic Extractors for Bit-Fixing Sources and Exposure-Resilient Cryptography

We give an efficient deterministic algorithm that extracts Ω(n2γ) almost-random bits from sources where n 1 2 +γ of the n bits are uniformly random and the rest are fixed in advance. This improves upon previous constructions, which required that at least n/2 of the bits be random in order to extract many bits. Our construction also has applications in exposure-resilient cryptography, giving exp...

On Perfect and Adaptive Security in Exposure-Resilient Cryptography

We consider the question of adaptive security for two related cryptographic primitives: all-or-nothing transforms and exposureresilient functions. Both are concerned with retaining security when an intruder learns some bits of a string which is supposed to be secret: all-or-nothing transforms (AONT) protect their input even given partial knowledge of the output; exposure-resilient functions (ER...

Exposure-resilient cryptography

We develop the notion of Exposure-Resilient Cryptography. While standard cryptographic definitions and constructions do not guarantee any security even if a tiny fraction of the secret entity (e.g., cryptographic key) is compromised, the objective of Exposure-Resilient Cryptography is to build information structures such that almost complete (intentional or unintentional) exposure of such a str...

Exposure-Resilient Functions and All-or-Nothing Transforms

We study the problem of partial key exposure. Standard cryptographic definitions and constructions do not guarantee any security even if a tiny fraction of the secret key is compromised. We show how to build cryptographic primitives that remain secure even when an adversary is able to learn almost all of the secret key. The key to our approach is a new primitive of independent interest, which w...