Constructing secure obfuscation proved extremely difficult. An ideal version proved impossible in 2001, prompting researchers to tackle the weaker iO target, a roughly two-decade effort littered with failed attempts. The recent good news is that iO can now be built under reasonable security assumptions.
However, the downside is that the runtimes are, in Buterin’s words, “galactic”, efficient on paper but absurdly slow in practice.
Buterin likened the moment to when SNARKs, the zero-knowledge proofs now central to Ethereum’s scaling, were around 2010, before years of optimization transformed them from a curiosity into a functioning infrastructure. The idea is that obfuscation could travel the same path from theoretical breakthrough to usable tool, even if a single run today would be desperately expensive.
Privacy coins like Monero (XMR) already hide things on a live blockchain, so why does Buterin consider this unresolved? Because they hide different things. Monero hides transaction data, such as who paid whom and how much, through ring signatures, stealth addresses and confidential amounts.
Obfuscation in Buterin’s sense hides the logic of the program, the code itself, and not the data passing through it. As he says, iO hides code, not data. Monero has been dealing with transaction privacy for over a decade, but program obfuscation has never been put into production anywhere, and bridging that gap is the goal of its message.
