Ethereum co-founder Vitalik Buterin has published the third and final post in his series on indistinguishability obfuscation, focusing on Local Mixing. This approach draws on symmetric cryptography techniques from hash function design rather than lattices, elliptic curves, or prime factorization. It scrubs internal logic traces from logic-gate circuits through a pipeline of reversibility, hardening, gadgetization, mixing, and obfuscation, using junk gates, shuffling, and block swaps to conceal structure while preserving functionality. Buterin calls it a wild and risky bet built on failed white-box cryptography attempts, though AI-assisted research could accelerate maturation from decades to years. Obfuscation remains cryptography’s final frontier, enabling encrypted programs that run on ordinary inputs and, paired with blockchain, approximate trustless trusted third parties for private, collusion-resistant voting.