Bitcoin rollup could increase transaction speed by 10x, developer claims

A team of cryptocurrency developers has announced detailed plans to enable rolling up of transactions in Bitcoin, a common practice in cryptocurrencies that was thought to be impossible with its granddaddy blockchain.

Rollups are a decentralized system for bundling crypto transactions off-chain before being settled on-chain in more data-efficient batches, and have historically been used as a scaling solution for Ethereum. The authors of the proposed Bitcoin framework say rollups will do more than just increase capacity.

“These bring full Turing functionality to Bitcoin,” said Edan Yago, co-author of the Bitcoin Rollup Framework. BitSNARK and Grailwith a message to Decryption. Turing completeness means Bitcoin can use smart contracts, which enables decentralized finance (DeFi) and other applications found on other blockchains.

“Initially, we expect it to be more than 10 times as large as Bitcoin, with full security,” he continued. In another presentation earlier this year, developers claimed that, at least in theory, Bitcoin rollup transactions could have infinite scalability in terms of both throughput and speed.

Yago is a contributor to Bitcoin DeFi platform Sovryn (SOV), which announced the development of Bitcoin rollup platform BitcoinOS in January. Unlike other scaling proposals, BitcoinOS does not require soft or hard fork upgrades to Bitcoin Core, which is intentionally evolving and robust to change.

Their white paper, published last week, features two innovations.

One is called BitSNARK, which is a software library for validating zkSNARKS on Bitcoin. zkSNARKS are zero-knowledge cryptographic proofs of completed transactions with no other details included or exposed.

BitSNARK is a core component of our second innovation, Grail, a practical and scalable implementation of BitSNARK for creating Bitcoin rollup bridges. Grail bridges allow Bitcoin blockchain users to move BTC (and other assets) back and forth between layer 2 networks (rollups) in a near-trustless manner.

According to Yago, Bitcoin's rollup design shares elements of both Ethereum's ZK rollup and optimistic rollup.

“Bitcoin rollups are the new beast,” he said. “They use his ZK proof, but verify it through a challenge/response sequence, similar in some ways to an optimistic rollup.”

Moving BTC through BitcoinOS still requires an intermediary agent called an “operator” who helps the bridge process deposits and withdrawals. These operators constantly monitor the activities of their fellow operators and prevent them from stealing users' coins or processing any kind of dishonest bridge transactions.

“As long as even one operator is honest, the system maintains its integrity,” Yago said.

Yago also said that the decentralized operator set has “no theoretical limit to the number of participants.” New operators can join and old members can leave by following certain steps. Sovereign said he is working on building bridges that work effectively. Over 100 operators.

The proposed rollup system is derived from Robin Linus' innovative BitVM framework, which last year introduced the ability to compute anything with Bitcoin.

The group says that unlike BitVM, BitSNARK is purpose-built for SNARK verification, overcoming the practical limitations and inefficiencies of its predecessors in supporting Bitcoin rollup bridges.

“Program size is improved by orders of magnitude, reducing challenge/response protocol length by as much as 50% for the types of computations required by bridges,” the white paper states.

The Grail bridge implementation also resolves a significant limitation of the BitVM bridge that was noted earlier this month. Cryptocurrency developer Tyler Whittle argues that if bridge operators are forced to process large-scale withdrawals that exceed their liquidity, users of such bridges could lose all their funds. did.

“Grail provides users with consistent withdrawal functionality,” the whitepaper says. “The application of fee markets for priority withdrawals and the ability to extend operators via dynamic membership will enable continued smooth operation of withdrawals.”

Yago said that if Sovryn's BitcoinOS works, it could make rival L2 and sidechains such as Liquid, Rootstock, and Stacks “totally obsolete.” Sidechains don't have the direct security of the Bitcoin network or a decentralized Bitcoin peg, but Rollup has both, which is a huge improvement.

In fact, the bridge is so decentralized that no one, not even the government, may be able to compromise it, Yago said.

“This system is absolutely designed to defeat nation-state level attackers,” Yago said. “One honest programmer in his basement can defeat a coalition of nation-states.”

Edited by Ryan Ozawa.