Ernst & Young’s Nightfall: A private-public blockchain

Ernest & Young’s Nightfall blockchain is attempting to combine public and private features to create a truly hybrid blockchain solution.

The latest blockchain service deployed by EY integrates private-public functionalities in order to maximise its utility for corporations and institutional players, and has now enabled corporations to privately use Ethereum technology.

Essentially, the team behind Nightfall understands the importance of integrating privacy tech, such as ZK-snarks, into a blockchain for smart contracts and micro-services.

Let’s take a look at how it works, how it’s being implemented, and what to expect from Nightfall in the near future.

EY’s Nightfall – linking private to public

There is a distinct divide between private and public in the world of blockchain technology.

On the one hand, there are ever-growing public networks like Ethereum with billions of dollars of investment and millions of users.

On the other hand, there are thousands of private blockchains run by enterprises, mostly on Hyperledger.

Enterprise use of public blockchains is very limited because there is no privacy for business transactions or contracts.

That is, until Nightfall came along. EY’s goal is to bridge the gap between public and private blockchains by enabling secure private transactions over public networks using zero-knowledge proofs. Simple, right?

Nightfall integrates a set of smart contracts and micro-services as well as a ZK-snarks toolkit to enable standard ERC-20 and ERC-721 tokens to be transacted on the Ethereum blockchain with complete privacy.

It is an experimental solution and is still being actively developed. The EY team decided to share their research work in the belief that this will speed up the adoption of public blockchains.

A challenge by the Nightfall team

Imagine the following business scenario:

There are products travelling through a supply chain process from supplier to manufacturer and from manufacturer to pharmacy with the help of a transporter.

The aim is to find out how many of what products are sent to the manufacturer and then how many products the manufacturer uses to assemble the final products in order to send to the pharmacy.

The challenge? How can these parties share only the required information without losing privacy over the rest of the data?

By using an approach that involves zero-knowledge proofs, it’s possible to accomplish the challenge above.

According to EY’s GitHub page:

“Any asset that needs to be tracked is tokenised into a non-fungible token commitment while any payment that needs to be made against this asset is tokenised into a fungible token commitment.

“Processes are built over the movement of these token commitments using business logic executed through smart contracts.

“But to maintain privacy for business operations regarding what asset has been transferred between which two parties and how much was paid for it, we use 7 different ZKP protocols.”

The zero-knowledge proofs for these protocols are generated off-chain while the verification of these proofs happens on-chain.

Therefore, formal verification is accomplished and only the right information is shared between parties, giving participants privacy over their transactions.