How to Generate and Use Universal Samplers
- Cite this paper as:
- Hofheinz D., Jager T., Khurana D., Sahai A., Waters B., Zhandry M. (2016) How to Generate and Use Universal Samplers. In: Cheon J., Takagi T. (eds) Advances in Cryptology – ASIACRYPT 2016. ASIACRYPT 2016. Lecture Notes in Computer Science, vol 10032. Springer, Berlin, Heidelberg
A random oracle is an idealization that allows us to model a hash function as an oracle that will output a uniformly random string given any input. We introduce the notion of a universal sampler scheme that extends the notion of a random oracle, to a method of sampling securely from arbitrary distributions.
We describe several applications that provide a natural motivation for this notion; these include generating the trusted parameters for many schemes from just a single trusted setup. We further demonstrate the versatility of universal samplers by showing how they give rise to simple constructions of identity-based encryption and multiparty key exchange. In particular, we construct adaptively secure non-interactive multiparty key exchange in the random oracle model based on indistinguishability obfuscation; obtaining the first known construction of adaptively secure NIKE without complexity leveraging.
We give a solution that shows how to transform any random oracle into a universal sampler scheme, based on indistinguishability obfuscation. At the heart of our construction and proof is a new technique we call “delayed backdoor programming” that we believe will have other applications.