CertiK, the largest Web3 security services provider, has completed a formal verification of zkWasm, a general-purpose zero-knowledge virtual machine used to generate cryptographic proofs of program execution, according to information shared with Finbold on September 28, 2026.
Using the Coq proof assistant, CertiK’s research team mathematically proved that zkWasm’s core circuits are sound, providing a level of assurance that goes beyond traditional audits or testing.
zkWasm allows developers to prove that a WebAssembly program executed correctly without revealing the underlying computation, a capability increasingly relied upon in blockchain infrastructure, rollups, and privacy-preserving applications.
Because zero-knowledge virtual machines sit at the foundation of these systems, a single flaw in their underlying circuits can silently undermine every proof built on top of them.
Mathematical proofs cover zkWasm’s full instruction set and establish two core guarantees
Formal verification takes a fundamentally different approach to conventional security review. Rather than searching for known bug patterns, CertiK’s team translated zkWasm’s Halo2 circuit logic directly into the Coq theorem prover and constructed machine-checked mathematical proofs that the circuits behave exactly as intended.
The verification establishes two central guarantees: that every accepted computation trace represents a valid execution of the underlying program, and that the prover cannot construct a valid proof for an incorrect execution.
The effort covers zkWasm’s full instruction set, including arithmetic and bitwise operations, memory access, control flow, and function calls, with verification spanning every major component from instruction execution to memory consistency and call-stack integrity.
CertiK describes this as one of the most comprehensive formal verification efforts applied to a production zero-knowledge virtual machine to date.
The research also identified and helped resolve subtle correctness issues uncovered during the verification process, underscoring the value of formal methods in surfacing edge cases that are difficult to catch through conventional review. Full technical details, including methodology and proof architecture, are documented in CertiK’s accompanying technical blog series.
The work builds on CertiK’s foundation in academic research from Yale University and Columbia University and reflects the company’s continued investment in formal verification as a core pillar of blockchain security.
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