Polychain Capital and Hack VC led a $18 million Series A funding round for Babylon Chain, a protocol working on Bitcoin (BTC) staking, bridging the decentralized finance (DeFi) ecosystem with the Bitcoin blockchain.

According to the Dec. 7 announcement, the funds will be used to support the development of Babylon’s Bitcoin Staking protocol, which enables proof-of-stake (PoS) networks to stake BTC, adding liquidity and security to emerging chains.

For context, a PoS chain is a type of blockchain that relies on participants to validate transactions. To be a validator and create new blocks, a participant must stake the chain’s native coin. The security and integrity of a PoS chain depend on the amount of coins staked. Bitcoin, however, uses a different mechanism, known as proof-of-work (PoW), where miners solve complex mathematical problems to validate transactions.

Babylon wants both worlds to be combined into one. The startup introduced its Bitcoin staking minimum viable product in October, claiming it would help reduce inflationar pressure on PoS chains that could rely on Bitcoin to attract capital through staking while strengthening the security of emerging chains.

According to the startup’s lite paper, its biggest challenge is to remotely “slash all safety violations without having a smart contract on the Bitcoin chain.” To address this issue, the protocol claims to use accountable assertions, finality gadgets, Bitcoin emulation and timestamps. “Our construction is modular, and can be used on top of all PoS consensus protocols. No soft or hard fork of Bitcoin is needed to implement our Bitcoin staking protocol,” Babylon wrote.

Staking could pave the way for more developers to build solutions on the Bitcoin network, which is one of the challenges facing the original blockchain. As the first and most prominent cryptocurrency, Bitcoin has a market capitalization of $847.8 billion at the time of writing. A Glassnode report found that 66% of its circulating supply has been dormant for at least a year.

“Babylon not only unlocks the largest blockchain asset, but can also make Bitcoin-backed security services (such as data availability service) possible for the broader blockchain ecosystem,” said Alex Pack, managing partner at HackVC.

Additional investors in the round included Framework Ventures, Polygon Ventures, Castle Island Ventures, OKX Ventures, Finality Capital, Breyer Capital, Symbolic Capital and IOSG Ventures.