zkVMs are redefining execution. They verify logic through cryptographic proofs, not execution. Bitcoin is entering this model through relays and inclusion proofs. Execution is programmable, but risk surfaces have shifted. Details below.

Security depends on circuit soundness, compiler fidelity, and isolation boundaries. A valid proof can represent invalid logic if the constraint model is incomplete or misaligned.

Spearbit evaluates zkVM systems at the constraint level. Reviews cover encoding accuracy, proof behavior under adversarial input, and interactions with Bitcoin data and bridge logic.