A senior executive at Big Four auditor Ernst & Young (EY) thinks blockchain will revolutionize commerce – if the community can solve its privacy issues.

“Blockchain is going to be the tool that ties together not just individual companies, but whole business ecosystems and networks,” says EY global innovation lead Paul Brody. “Enterprises will not go on to the public mainnet without privacy and security.”

In this interview with Christine Kim, Brody discusses a range of privacy solutions, including Nightfall, EY’s open source code repository. The protocol integrates zero-knowledge proofs with smart contracts, enabling private transactions on the public ethereum blockchain.

Procurements are one particular use case. Any enterprise that can leverage different pricing models often leaves money on the table when making purchase orders. Nightfall, however, can set up smart contracts “without any additional administrative or operational overhead” that execute at the best price, Brody argues.

Although the basic product remains free on GitHub, Nightfall’s transaction costs are still high at around $10. Brody thinks these costs could drop below $1 in the coming year, meaning that Nightfall could eventually be more cost effective than private, permissioned blockchains.