Ethereum zero-knowledge proof scaling system zkSync Era has unveiled its answer to Optimism’s Superchain concept in the form of ZK Stack.
It’s a modular framework for a series of ZK-powered custom blockchains called yperchains, which will operate as a new layer on top of the existing layer-2 protocol. The chains will be composable and interoperable, enabling almost-instantaneous transfers of liquidity and flash loans between protocols in the system, which is not possible between L1 blockchains.
It shares some similarities to the Superchain network of L2s unveiled by Optimism when it announced Coinbase’s BASE would be the first addition.
Alex Gluchowski, the co-founder and CEO of zkSync, told Cointelegraph that the system did away with the need for clunky and insecure token bridges, which are the weak point exploited by many of the biggest crypto hacks.
“We have the ZK Stack now available for people to start building and we already have the first products we’re working with to build it, and this will be live on the testnet definitely by the end of the year,” he said.
While Gluchowski expects more than 95% of DApps will still port over directly to the L2, the Hyperchains will likely be used by projects with specific requirements around privacy, speed and data availability. Games, social networks, low-latency exchanges and banks are some of the potential users.
After a slightly muted launch, zkSync Era has grown in leaps and bounds, notching up almost $620 million in total value locked. It now processes 20.8 million transactions per month at around 8 transactions per second, peaking at 12 TPS.
Gluchowski compared the ZK Stack to the framework of the internet, which enables a limitless expansion of the network. “You can always add more servers, more cables, more connections and grow it from 1000 servers to 1 million servers to 1 billion servers,” he says. “Blockchains today are not having this property.”
ZK Stack will make use of recursive scaling, where transactions are batched into a ZK proof, and then a series of those ZK proofs are batched into a single proof for progressively greater compression. This means the system can theoretically scale up to any demand.
“We can still combine multiple proofs from multiple protocols together and paste them together recursively,” he explained, adding:
“Every once in a while we will just publish one single proof on Ethereum which trustlessly incorporates the proofs of all these chains.”
The code is free and open source under the MIT/Apache license. zkSync told Cointelegraph that a couple of big partners are already on board to trial the system, but did not provide further details.
While the ZK Stack can theoretically connect other ZK roll-ups, such as Polygon’s zkEVM, ConsenSys’ Linea or StarkNet, Gluchowski indicated that this was unlikely. So the ZK Stack looks unlikely to solve the interoperability problem with ZK rollups any time soon.