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Paper: Collusion Resistant Broadcast and Trace from Positional Witness Encryption

Authors: Rishab Goyal Satyanarayana Vusirikala Brent Waters DOI: 10.1007/978-3-030-17259-6_1 Search ePrint Search Google PKC 2019 An emerging trend is for researchers to identify cryptography primitives for which feasibility was first established under obfuscation and then move the realization to a different setting. In this work we explore a new such avenue—to move obfuscation-based cryptography to the assumption of (positional) witness encryption. Our goal is to develop techniques and tools, which we will dub “witness encryption friendly” primitives and use these to develop a methodology for building advanced cryptography from positional witness encryption.We take a bottom up approach and pursue our general agenda by attacking the specific problem of building collusion-resistant broadcast systems with tracing from positional witness encryption. We achieve a system where the size of ciphertexts, public key and private key are polynomial in the security parameter $\lambda$ and independent of the number of users N in the broadcast system. Currently, systems with such parameters are only known from indistinguishability obfuscation.
BibTeX
@inproceedings{pkc-2019-29295,
title={Collusion Resistant Broadcast and Trace from Positional Witness Encryption},
booktitle={Public-Key Cryptography – PKC 2019},
series={Lecture Notes in Computer Science},
publisher={Springer},
volume={11443},
pages={3-33},
doi={10.1007/978-3-030-17259-6_1},
author={Rishab Goyal and Satyanarayana Vusirikala and Brent Waters},
year=2019
}