BitcoinOS Has Completed a Bridgeless Transfer of Bitcoin to the Cardano Blockchain and Back

BitcoinOS has completed a bridgeless transfer of Bitcoin to the Cardano blockchain and back. This process did not require any custodians, vaults, or third-party bridges, and used zero-knowledge cryptography.

According to an X thread, BitcoinOS performed what it describes as the first bridgeless cross-chain transaction between Bitcoin and Cardano. On May 4th, 2025, BitcoinOS deployed its BitSNARK protocol and the new xBTC token standard as part of this demonstration.

A user locked 1 BTC on Bitcoin Layer 1 and minted xBTC. This wrapped asset uses cryptographic proofs to show that another party holds the original Bitcoin off Layer 1.

xBTC differs from earlier wrapped Bitcoin models because it doesn’t require a custodian or vault. Its operation, enabled through zero-knowledge cryptographic proofs, allows asset ownership maintained on-chain. The transfer was conducted by Bitcoin and Cardano wallets, without the involvement of intermediaries.

The demo featured Sundial Protocol, a hybrid Layer 2 solution for Bitcoin and Cardano. From a Bitcoin wallet, Sundial’s wallet on Cardano received 1 xBTC token. This was when the asset moved from one blockchain to another, becoming a UTXO on Cardano.

Programmable Bitcoin With xBTC

xBTC introduces a programmable format for Bitcoin while remaining non-custodial. This token was developed by BitcoinOS to operate similarly to wETH on Ethereum, but in the Bitcoin framework. It is a programmable and cryptographically transferable token across blockchains that does not rely on a central authority.

After receiving the token on Cardano, Sundial transferred it to a wallet owned by ADA Handle, a Cardano-based on-chain identity project. This proved that xBTC could move within the Cardano ecosystem like any other native token. Finally, the token was returned to the Bitcoin blockchain, burned, and the original BTC unlocked, completing a round-trip without the use of traditional bridge mechanisms.

The process relied on zero-knowledge proofs generated and verified by BitSNARK, which was open-sourced by BitcoinOS in March 2025. This allowed validation of the transaction without revealing underlying private data, maintaining security while proving authenticity.

Traditional cross-chain bridges have suffered from many security failures, with over $2 billion lost in related exploits since 2022. BitcoinOS aims to remove these risks by avoiding bridges entirely and using cryptographic proof systems instead.

The bridgeless model attempts to reduce single points of failure while enabling interoperability between major blockchains.

BitcoinOS claims the system does not compromise Bitcoin’s security or trustless model. Edan Yago, a core contributor at BitcoinOS, said users have not explored Bitcoin’s broader use cases due to technical limitations, not because they prefer simplicity. The team believes xBTC and similar technologies can make Bitcoin more usable in the wider decentralized finance ecosystem.

Cardano founder Charles Hoskinson recently discussed the blockchain industry entering a new development phase. He said this phase must focus on scaling solutions for real-world problems.

His comments came amid Cardano’s development of Midnight, a data protection-focused sidechain built to support regulatory-friendly digital assets, including stocks.

The demonstration by BitcoinOS fits into this wider push for scalable, privacy-respecting, and secure blockchain applications. By showing Bitcoin can interact directly with Cardano in a secure, decentralized manner, the project aligns with this next phase of blockchain evolution.