What is a Sovereign Rollup? Rollkit shows second layers for Bitcoin

Just a few months after the very first NFT was written into Bitcoin, developers are trying to fill the ancient blockchain with another new age technology: rollups.

At least that’s what Rollkit—a self-described “modular framework for rollups”—is.claimed over Twitter on Sunday, revealing a research integration that would allow for “superb rollups” on Bitcoin.

According to Rollkit, its new rollup solution allows users to produce rollups by retrieving and storing data on the Bitcoin blockchain. It was inspired by Ordinals, the Bitcoin NFT protocol that showed developers that users – using Taproot – could input arbitrary data to the blockchain.

In the traditional sense, rollups are groups of transactions that are “rolled up” off-chain into one transaction, and then posted to Ethereum as a single on-chain transaction. This helps free up block space and reduce transaction costs on the network, while also inheriting the settlement assurances of the base chain.

A sovereign rollup is one that doesn’t need a smart contract or use a settlement layer for validation – scalable and secure and with the “sovereignty” of a layer 1.

Some proponents of Ethereum, a network known for using layer-2 “rollups” as a transaction scaling solution, have taken issue with Rollkit’s use of the term.

Ryan Berckmans, a Web3 and Ethereum investor, so on Twitter that the sovereign pool “is actually an alt L1 that stores its block data on Bitcoin.”

According to Alexei Zamyatin, founder of Bitcoin DeFi protocol Interlay, sovereign rollups as proposed by Rollkit inherit “nothing” of Bitcoin’s security.

“Data availability – okay, but frankly, it’s been used since 2012,” he continued. “The entire post describes ‘I’m writing some data to Bitcoin’ with fancy buzzwords.”

Rollkit is still optimistic about the possibilities.

“This new integration expands the possibilities of rollups, and also has the potential to help start up a healthy blockspace fee market on Bitcoin, enabling a more sustainable security budget,” the company writes.

Some compare superb rollups to Stacks, a high functionality layer 1 protocol that settles the blocks on the Bitcoin blockchain for security purposes. Stack’s co-founder Muneeb Ali so on Twitter that this is an apt comparison, but noted some key differences.

On the one hand, it takes 150 Stacks blocks for a transaction to reach “Bitcoin finality” on Stacks, but only 1 with supreme rollups. On the other hand, Stacks blocks publish their data to Bitcoin efficiently by just hashing the data on-chain, while supreme digests publish all the data.

“The technically challenging part for both the Stacks layer and sovereign rollups is moving BTC in and out of the layer,” Ali said. “The decentralized BTC pin is the most important part.”