Vitalik: Obfuscation Could Power Trustless Blockchains

Ethereum co-founder Vitalik Buterin has highlighted obfuscation as one of the most powerful ideas in cryptography, but noted that it remains far from practical use. In a June 29 blog post, Buterin explained that obfuscation hides code, not data itself, allowing users to interact with a program and get the right result without seeing its inner workings.

Obfuscation is a type of indistinguishability obfuscation (iO), which means that two programs with the same function should look impossible to tell apart after being obfuscated. Buterin believes that this technology could enable private, trustless applications on blockchains, but notes that current runtimes make it impractical for real-world use.

Buterin also discussed how blockchains can solve state limits by providing a shared state that users can verify, which makes obfuscation and blockchains useful together. He used voting as an example of a protocol where users could avoid relying on a committee that must behave honestly, and instead rely on the blockchain to track shared state.

However, Buterin noted that researchers still need to optimize current lattice-based constructions or find new methods outside lattice cryptography to make obfuscation practical. He outlined several possible paths forward, each carrying trade-offs between speed and security.