Blockchain computer programs are pretty smart—that’s why we call them smart contracts—but they’re also pretty weak. If they’re going to achieve many of the lofty, world-changing goals that blockchain proponents say they will, like revolutionize health care and the energy industry and give people back control of their personal data online, they’re going to need to be run in a whole new way. That’s where Dawn Song’s new startup, Oasis Labs, comes in.

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The cryptocurrency world is overflowing with big claims, but Song is a well-known computer science professor at UC Berkeley and a MacArthur fellow (as well as one of MIT Technology Review’s 35 Innovators Under 35 in 2009). And a number of big-name funders seem to think her company, Oasis Labs, is on to something. This week, the startup announced that it has raised $45 million in a private token presale to a group of high-profile cryptocurrency investors and Silicon Valley venture capitalists. It also became the first project to get backing from Andreessen Horowitz’s new $300 million crypto fund.

Song says Oasis Labs has developed new “privacy preserving” smart-contract technology that overcomes fundamental limitations of today’s most popular smart-contract platform, Ethereum. She and several colleagues described a major component of the system in a recently published research paper (PDF).

Ethereum and similar smart-contract systems have limited utility for two main reasons, according to Song. First, the network’s rules generally require that every node execute every smart contract—that’s how the network reaches consensus. “Even when you have 100,000 nodes, the capacity of the network is still the same as one node,” she says. That severely constrains its performance. Second, today’s smart contracts can’t assure the confidentiality of sensitive data. Blockchains were built to be transparent! That’s why so many theoretical blockchain applications are still stuck on the drawing board.