Bitcoin Developers Working With StarkWare, Blockstream Claim Breakthrough on New Features

A group of top Bitcoin developers collaborating across multiple teams is claiming a breakthrough on the oldest and largest blockchain, outlining a way of adding a type of programming known as "covenants" that could unlock crucial functionality such as new wallet and vault features and more efficient layer-2 protocols.

Importantly, the technique would not require changes to Bitcoin's main underlying code, a notoriously fraught process where consensus is typically seen as the threshold required to greenlight major upgrades known as a "soft fork."

The announcement was detailed on Thursday in a research paper titled, "ColliderScript: Covenants in Bitcoin via 160-bit hash collisions."

The publication comes as Bitcoin, the oldest and largest blockchain, has attracted hordes of developers trying to add programmability and additional network layers that could lead to not only more applications being built atop the peer-to-peer network but also faster and cheaper venues for transaction execution. The goal is to catch up to what Ethereum, the second-largest blockchain, has achieved — but with Bitcoin's famously robust security.

'Pretty awesome idea'

The team was led by Ethan Heilman, who separately is one of the authors of a proposed technique known as OP_CAT that could increase Bitcoin's programmability.

However, that effort would require changes to the Bitcoin software, as would a separate proposal for covenants known as OP_CTV, proposed by the developer Jeremy Rubin.

Other authors of the new research paper include Victor Kobolov and Avihu Levy of the StarkWare project and Andrew Poelstra, a longtime Bitcoin developer who currently serves as head of research at Blockstream.

StarkWare's official account on X posted a link to the paper on Thursday, writing:

Until recently, it was believed that implementing covenants on Bitcoin would require a soft fork of an additional opcode, such as dedicated ones like OP_CTV or indirect ones like OP_CAT. In this paper, we show that covenants may already be feasible on Bitcoin today without any soft fork. While our solution is computationally intensive, we believe there’s significant room for optimization.

Robin Linus, a Bitcoin developer who has made waves for a project known as BitVM and more recently BitVM2 that could unlock greater programmability, told CoinDesk in a Telegram message that the research paper was "not really practical" in its current form but represented a "pretty awesome idea."

"It would cost like north of $10m to execute such a covenant, but the idea behind it is ingenious," Linus wrote. "I hope people will try to come up with optimizations to make it practical."