How does ColliderVM, StarkWare’s Bitcoin bridge play, stack up?
It is a section from the 0xResearch e-newsletter. To learn full editions, subscribe.
Bitcoin is a dumb base layer. In its native scripting setting, computation is stateless, that means every transaction is validated independently — with no built-in reminiscence of prior occasions or intermediate outcomes. This limits Bitcoin to easy, one-off logic like multisig, timelocks or a primary inheritance contract.
True Bitcoin layer-2 (L2) networks will want stateful computation on Bitcoin, which is the place StarkWare’s newly proposed ColliderVM is available in.
The concept is to let Bitcoin validate complicated computation throughout transactions, one thing which not way back was thought to require a brand new mushy fork improve. Whereas nonetheless within the early phases of improvement, ColliderVM joins a rising class of trust-minimized L2 bridge architectures that search to bypass the present stalemate round new Bitcoin opcodes like CTV or CAT. No forks required.
ColliderVM builds on concepts from BitVM2 and StarkWare’s earlier ColliderScript, utilizing hash-collision-based puzzles to go information throughout Bitcoin transactions. This makes it “no less than x10,000 extra environment friendly” than ColliderScript, in line with StarkWare co-founder Eli Ben-Sasson.
However as BitVM creator Robin Linus famous to Blockworks, that will not be as spectacular because it sounds, since “ColliderScript is impractically sluggish.”
ColliderVM avoids the fraud proofs central to BitVM2. Which means operators aren’t pressured to prepay withdrawals whereas ready for fraud home windows to run out. As a substitute, computation is validity-based and verified straight on Bitcoin.
“Consider this as step two on the journey to ship [zk validity proofs],” Ben-Sasson advised Blockworks.
The tradeoff is price. As Bitcoin PIPES creator Misha Komarov places it: “It requires about 30 hours of the entire Bitcoin community hash fee compute to spend one covenant. [That] ends in a price of tens of millions of {dollars} [he estimates $40m] per tx.”
Ben-Sasson acknowledges that ColliderVM continues to be costly, and never prepared for prime time. “The newly launched analysis is essential as a result of it exhibits that it really works — not that it’s financially viable,” he stated.
Nevertheless, ColliderVM’s capital effectivity and ease, without having for onlookers or interactive problem protocols, could attraction to builders annoyed by BitVM2’s complexity.
Linus himself is wanting ahead to additional Bitcoin upgrades. “CTV is nice for BitVM,” he stated, particularly when paired with CSFS to “remove the existential honesty assumption” and simplify bridge logic. ColliderVM, alternatively, circumvents the necessity for CTV completely — however at the price of real-world feasibility, for now. That might change with the arrival of specialised {hardware}.
In the meantime, PIPES represents an alternate method — one most popular by Botanix Labs’ co-founder Willem Schroé. In his view, BitVM is “too complicated,” and ColliderVM is “good, however energy-intensive.” PIPES is “quite simple, very clear, however very theoretical and won’t work.”
Komarov agrees. “PIPES, compared to this hash collisions trick, are far more experimental from the theoretical standpoint,” he advised Blockworks. “However as soon as they work, they’re less expensive.”
Schroé has robust views on the bridge verification house. No matter what method turns into production-ready first, he thinks they do one thing essential: They present customers need covenant-like conduct.
“Bitcoin Core will not be even desirous about covenants,” Schroé stated. “However PIPES and Collider let you present that demand.”
