Implicit Computational Complexity of Subrecursive Definitions and Applications to Cryptographic Proofs

Abstract

AbstractWe define a call-by-value variant of Gödel’s System \(\mathsf {T} \) with references, and equip it with a linear dependent type and effect system, called \(\mathsf {d}\ell \mathsf {T} \), that can estimate the complexity of programs, as a function of the size of their inputs. We prove that the type system is intentionally sound, in the sense that it over-approximates the complexity of executing the programs on a variant of the CEK abstract machine. Moreover, we define a sound and complete type inference algorithm which critically exploits the subrecursive nature of \(\mathsf {d}\ell \mathsf {T} \). Finally, we demonstrate the usefulness of \(\mathsf {d}\ell \mathsf {T} \) for analyzing the complexity of cryptographic reductions by providing an upper bound for the constructed adversary of the Goldreich-Levin theorem.KeywordsType SystemFunction SymbolTyping RuleType InferenceTyping JudgementThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.