The Internet Computer blockchain is integrated with the Bitcoin blockchain to make powerful smart contract functionality available for Bitcoin through a direct, bridgeless, integration of the two blockchains. "Direct" in this context means that there are no additional parties required, such as bridges or other types of intermediaries, resulting in a much cleaner and more secure integration.
What new capabilities are possible from this integration?
- Canisters can have Bitcoin addresses, and therefore can receive and hold bitcoin directly on the Bitcoin blockchain.
- Canisters can access the balance and UTXO set of Bitcoin addresses.
- Canisters can securely sign Bitcoin transactions.
- Canisters can submit Bitcoin transactions to the Bitcoin network.
All of this is made possible by (1) the Internet Computer integrating with Bitcoin at the protocol level and (2) canisters being able to securely hold and use ECDSA keys by means of a novel protocol for chain-key signatures, based on threshold ECDSA. The Internet Computer is among the first blockchain networks performing such direct integration with other blockchains and has built a novel technology foundation for this purpose.
If you'd like to deploy a Bitcoin Dapp of your own, we recommend checking out these Developer Docs: Deploying Your First Bitcoin Dapp and Developing Bitcoin Dapps Locally.
After the Bitcoin mainnet release (general availability release) of the Bitcoin feature, a Chain Key Bitcoin (ckBTC) Canister will be made available. The ckBTC canister will provide on-chain Bitcoin on the IC, which looks and feels like wrapped Bitcoin, but has a much stronger underlying trust model because of its decentralized architecture and using threshold ECDSA instead of bridges.