Vitalik Buterin broke down Diamond iO, a new way to scramble a program so nobody can read its secret logic, while it still runs and returns the right answers.

The idea, called obfuscation, is often described as a holy grail of cryptography. It could power truly private apps, like secret onchain voting or programs that safely hold private keys, with no middleman to trust.

The catch has always been speed. Older designs were so slow they were basically theoretical. Diamond iO, built by the Machina iO team, combines two encryption techniques into a simpler design and cuts the runtime from what Vitalik calls "galactic" to "planetary" scale. It is still too slow for real use today, but he says it may be only a few optimizations away.