New Bridge Would Help Fix Crypto's Hacking Woes, Researcher Behind Patoshi Pattern Says

Co-founder and chief scientist at RootstockLabs, Lerner is one of the architects behind Union, a new Bitcoin bridge design built on BitVMX – a framework designed to enable complex computation and verification on Bitcoin. RootstockLabs' bridge, Lerner says, is designed to replace federated signer models such as Liquid and custodial systems backed by firms such as BitGo's Wrapped Bitcoin (wBTC) with cryptographic dispute resolution settled directly on Bitcoin itself. 

The weak link 

The project arrives as bridges remain one of crypto's weakest security points. In April, hackers stole about $292mn from KelpDAO's LayerZero bridge after exploiting a verification system that depended on a single approval pathway to validate withdrawals. 

Lerner argues most bridge designs remain vulnerable because too much trust is concentrated in a small group of operators or validators. His proposed model instead allows any single honest participant to challenge and block suspicious withdrawals before they are settled on Bitcoin. 

One honest participant 

Rather than requiring a majority of operators to remain honest, the Union bridge requires only one. Adrian Eidelman, co-founder of RootstockLabs, described the design principle: "Out of all the participants securing the bridge, only one of them needs to be honest for your BTC to stay safe." 

The practical consequence is that the more participants Union brings into its network, the stronger it could become. "The bar for an attacker isn't 'corrupt the majority.' It's 'corrupt everyone, without exception,'" Eidelman said. "That's a fundamentally harder problem." 

"Moving Bitcoin across chains should be routine. The fact that bridge risk is still a topic of conversation in crypto today is a sign of how immature the space still is. In five years, that conversation should be over," Eidelman said. 

Operators on Union are required to post security bonds to participate in the network. Lerner said BitVMX reduces those requirements significantly compared with other bridge designs, lowering the minimum deposits from tens of thousands of dollars to roughly $1,000 per operator. 

The lower barrier is intended to keep participation open rather than restricting the bridge to a small group of approved validators. But it also raises another question: whether attackers could cheaply flood the network with malicious operators or attempt to obstruct withdrawals. 

Lerner said the bonds are designed less as a trust mechanism than as an economic deterrent against spam and fraudulent challenges. Operators that obstruct the system risk losing collateral, while liquidity providers can advance funds to users if withdrawals become delayed by malicious participants. "The design makes that behaviour either ineffective or economically self-defeating," he said. 

Scaling without changing Bitcoin 

Long before his research into Satoshi-era wallets, Lerner said he had been focused on Bitcoin scalability. By the mid-2010s, as disputes over block sizes and protocol changes escalated into the so-called "blocksize wars," he concluded that scaling Bitcoin through changes to the base layer was politically and technically unrealistic. 

That pushed him towards a different approach: building layers on top of Bitcoin rather than modifying Bitcoin itself. But those systems still required bridges connecting back to the network – infrastructure Lerner believes evolved in ways that conflicted with Bitcoin’s original philosophy. 

"The current generation of bridges reflects the priorities of the chains they were built for: fast, flexible, and willing to make compromises in trust to ship quickly," he said. "Satoshi's whole approach was to minimize trust wherever possible, even at the cost of speed, convenience, or feature richness. A bridge secured by a handful of signers, or by a validator set with its own token and its own incentives, would sit uncomfortably with that philosophy." 

Lerner pointed to an early hint from Bitcoin's creator: Satoshi had discussed native primitives for verifying succinct cryptographic proofs on Bitcoin. "That tells you the appetite for cryptographic verification was there from the very beginning." 

The proposed new design comes with acknowledged limitations and risks. Lerner acknowledged that validating bridges remain theoretically vulnerable to a coordinated 51% attack in which Bitcoin miners censor fraud challenges and allow invalid withdrawals to pass through. To mitigate that scenario, the bridge retains an additional multisig layer called Powpeg for higher-value withdrawals. 

"The point isn’t that Union Bridge is invulnerable," Lerner said. "It’s that the attacks that have historically destroyed bridges, the majority trust failures, are no longer on the table."