This work suggests a path toward accelerating cryptographic research: as agents automate the proof-engineering burden, cryptographers can iterate more quickly on new constructions, obtain machine-checked assurance earlier, and bring trustworthy protocols from design to deployment faster.
Abstract
Cryptographic proofs are produced at a scale that increasingly exceeds the community's ability to verify them manually. Machine-checked proofs offer a path toward scalable proof verification, but writing proof scripts for expressive proof assistants such as EasyCrypt remains a major bottleneck: even when the high-level proof plan is known, converting it into proof tactics requires substantial reasoning effort. This paper presents ShannonProver, an agentic framework for automating cryptographic proofs. ShannonProver targets the setting in which a cryptographer provides the security model and a decomposition of the target theorem into lemma-level proof obligations, while the system automatically constructs EasyCrypt proof scripts for those obligations. We evaluate ShannonProver on a dataset of formal cryptographic proofs in EasyCrypt. The dataset spans textbook primitives, deployed protocols, and standardization efforts such as NIST proposals, and includes expert case studies drawn from a corpus that has not previously been available online. We show that ShannonProver can automate substantial portions of cryptographic proof engineering for case studies such as ChaChaPoly1305 and MEE-CBC. More broadly, this work suggests a path toward accelerating cryptographic research: as agents automate the proof-engineering burden, cryptographers can iterate more quickly on new constructions, obtain machine-checked assurance earlier, and bring trustworthy protocols from design to deployment faster.
Cryptographic code is critical infrastructure that must be correct, yet formally verifying production libraries remains difficult. Existing language-model proof systems solve isolated obligations with specifications and premises already given, leaving production-library verification unresolved. We present CryptoProver, an AI-based system that synthesizes internal specifications and Verus-checked proofs from high-level API contracts. Without changing executable code, CryptoProver constructs a new independent proof of curve25519-dalek and verifies RustCrypto's previously unverified chacha20 implementation against an RFC 8439 specification. These cryptographic lineages underpin deployed systems including Signal and Shadowsocks; Signal has an estimated 218M global downloads. The independent, human-led curve25519-dalek verification was developed publicly over eight months by five main contributors. Given the API contracts and a fixed trusted library of field specifications, arithmetic facts, axioms, and vstd, CryptoProver synthesizes the internal specifications and proofs in 11.4 hours with USD 466.99 in recorded API cost. CryptoProver follows a trust-first design principle: mechanical gates reject specification weakening, invented axioms, and cross-module breakage, while isolation blocks reference proof retrieval, including from git history.
Chuyue Sun, S. Fong, Zhiyi Kuang et al.· 0 citations
Pistis is introduced, an agentic, oracle-guided proof search that produces formal Lean proofs that satisfy faithfulness conditions and can accept or refute natural language proofs written by humans or AI, demonstrating that faithful formalization is useful as a proof-checking tool.
Tadd Mao, Tianjun Zhong, Dhruva Arekar et al.· 1 citation
Computer-aided cryptography (CAC) provides strong guarantees through mechanized proofs of security. SquirREL is a proof assistant specialized in CAC, but is restricted to the asymptotic setting, which limits its applicability. Recent theoretical work [1] adapted Squirrel’s underlying logic to the concrete setting through the introduction of a higher-order logic with errors. While this allows to prove precise security bounds on paper, it only provides a low-level logical calculus which lacks an implementation. Thus, it falls short of the CAC aims.In this paper, we use this low-level calculus to build the full-fledged set of features used in a proof assistant such as Squirrel, with a focus on reachability reasoning. We design higher-level logical mechanisms on top of this logic, including proof context management, introduction patterns, and boundannotated tactics. To do so, we introduce a proof term calculus with dedicated features for bounds, for which we design an elaborator. This elaborator can automatically infer bound-related manipulations, improving usability and reducing user inputs, and we theoretically argue for its usability through an erasability theorem. All these improvements have been implemented as an extension of Squirrel, and we provide empirical evidence of the applicability of our framework through case studies.
SymCert is presented, a framework implemented in Lean for building verified SMT-based analyses of Cedar policies that provide a verified symbolic compiler and authorizer for reducing policies to SMT formulas, a hierarchy enforcer for ensuring well-formedness of counterexamples, and a counterex-ample extractor for proving analysis completeness.
Relating low-level executable code to a high-level account of its behavior has been a central concern of programming-language research for decades. From formally verified compilers to translation validators, certifying compilers, and proof-carrying code, each approach chooses between laborious but foundational mechanized proofs and automation that costs completeness, generality, and an increased trusted base. Recently, large language models (LLMs) have begun to change the economics of formal verification. Agentic proof development is now capable of producing machine-checked proofs at a scale and speed that were previously out of reach. In this paper, we evaluate the capabilities of LLMs to produce foundational, machine-checked proofs of refinement between executable code and its high-level specification, as post hoc, per-artifact certificates. We study this in the context of the Ethereum Virtual Machine (EVM), a low-level virtual machine that executes smart contracts on the Ethereum blockchain. We build EquiVM, a foundational framework in Lean comprising an executable EVM semantics and a specification language that characterizes the intended behavior of smart contracts, but commits to no source language or compilation toolchain. In EquiVM, refinement is stated for deployed bytecode of arbitrary provenance, interaction with unknown code is part of the semantics, and each proof is a replayable, machine-checked certificate. No previous technique achieves this combination. Using frontier commercial LLMs, twenty-three real-world contracts are proved end to end with minimal human guidance, among them most of the MakerDAO stablecoin system, at up to a hundred million tokens and a hundred hours of proof time per contract. We conclude that foundational mechanized proofs can now be bought at the price of tokens, and that this shift can reshape how verification frameworks are architected.
