## CryptoDB

### Paper: Simplifying Game-Based Definitions

Authors: Phillip Rogaway Yusi Zhang DOI: 10.1007/978-3-319-96881-0_1 Search ePrint Search Google Slides CRYPTO 2018 Often the simplest way of specifying game-based cryptographic definitions is apparently barred because the adversary would have some trivial win. Disallowing or invalidating these wins can lead to complex or unconvincing definitions. We suggest a generic way around this difficulty. We call it indistinguishability up to correctness, or IND$\vert$C. Given games ${{\text {G}}}$ and ${{\text {H}}}$ and a correctness condition ${{\text {C}}}$ we define an advantage measure ${\mathbf {Adv}_{{{\text {G}}},{{\text {H}}},{{\text {C}}}}^{{\text {indc}}}}$ wherein ${{{\text {G}}}}$/${{{\text {H}}}}$ distinguishing attacks are effaced to the extent that they are inevitable due to ${{\text {C}}}$. We formalize this in the language of oracle silencing, an alternative to exclusion-style and penalty-style definitions. We apply our ideas to a domain where game-based definitions have been cumbersome: stateful authenticated-encryption (sAE). We rework existing sAE notions and encompass new ones, like replay-free AE permitting a specified degree of out-of-order message delivery.
##### BibTeX
@inproceedings{crypto-2018-28814,
title={Simplifying Game-Based Definitions},
booktitle={Advances in Cryptology – CRYPTO 2018},
series={Lecture Notes in Computer Science},
publisher={Springer},
volume={10992},
pages={3-32},
doi={10.1007/978-3-319-96881-0_1},
author={Phillip Rogaway and Yusi Zhang},
year=2018
}