Vitalik Buterin explores ‘local mixing’ cryptographic method

Ethereum co-founder Vitalik Buterin has released the third installment of his series on cryptographic obfuscation, focusing on a method known as ‘local mixing’. Unlike traditional cryptographic approaches, local mixing does not rely on elliptic curves, prime factorization, or lattices. Instead, it draws from the design principles of symmetric cryptography and hash functions.

The process involves transforming a circuit composed of logic gates—such as XOR, AND, and NOT—through a pipeline of reversibility, hardening, gadgetization, and mixing. This pipeline aims to scrub away traces of the internal logic while maintaining the original function. Buterin describes the approach as a ‘wild and risky bet’ because it operates within a field of previously failed attempts at white-box cryptography.

If successful, the technology could provide a quantum-resistant public-key encryption method with ciphertexts as small as 48 bytes, though public keys would require several megabytes. While the computational overhead is significant—with some versions causing logic gates to expand by approximately 80,000 times—it remains significantly more efficient than the expansion seen in fully homomorphic encryption.