International Association
for Cryptologic Research

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.