Ethereum co-founder Vitalik Buterin has published the third and final installment of his series on indistinguishability obfuscation, focusing on a method called local mixing. The post, released on Friday, August 21, 2026, follows Part I from June 29 and Part II from July 28, which examined lattice-heavy constructions and diamond iO.
Unlike earlier approaches, local mixing does not rely on elliptic curves, prime factorization, or lattices. Buterin described it as “a totally different way of doing cryptography,” with its closest relative being symmetric cryptography—the discipline behind everyday encryption and hashing.
The process begins with a circuit made of logic gates such as XOR, AND, and NOT. It then passes through stages: the original circuit, adding reversibility, hardening, gadgetization, mixing, and finally obfuscation. During mixing, junk gates are scattered through the circuit, the arrangement is shuffled, and small blocks are swapped for different gates that compute the same thing. Buterin noted that reversibility comes first because it makes the rest possible: a reversible gate can be rewritten as an arbitrary pile of other reversible gates with matching behavior, which is harder with an AND or OR.
Buterin called local mixing a “wild and risky bet” that sits on “a graveyard of failed attempts at white-box cryptography.” However, he noted that its authors believe more effort and a willingness to accept higher overhead could make the idea hold. One proposed shortcut is artificial intelligence, which could compress decades of hash function maturation into a few years.
He reiterated that obfuscation is the “final frontier of cryptography,” with the most rigorous constructions carrying “literally galactic” runtimes longer than the lifetime of the universe. When paired with a blockchain, obfuscation could enable a “trustless trusted third party,” supporting private, collusion-resistant voting without an M-of-N committee to trust.
