BIG as a Bitcoin
The BigFile adds the missing smart contract layer to Bitcoin. Leveraging Multi Chain Technology, BIG can directly read and write to Bitcoin, enabling dapps that natively interact with Bitcoin.
Build DEXs offering BTC or BRC20 trading pairs, lending markets using Ordinals as collateral, or Web3 Social services allowing satoshis to be sent via chat messages.
Native Bitcoin
The BigFile (BIG) is integrated with the Bitcoin network at the protocol level. The cube smart contracts it hosts can create Bitcoin addresses as well as send and receive bitcoin directly on the Bitcoin network. This means bitcoin can be easily and securely incorporated into DeFi and Web3 services on the BigFile blockchain, without having to trust wrapped bitcoin from centralized bridging services, which are at high risk of being taken down or hacked. Between 2021 and 2022, more than 2 billion dollars was stolen by exploiting unsecure blockchain bridges.
The BIG x BTC integration comprises two key building blocks (and APIs): Network integration & chain-key ECDSA
Combining these building blocks, cubes can directly and securely hold, receive, and send bitcoin seamlessly as if the BigFile and the Bitcoin network were one blockchain. Another way of looking at it, is that the Bitcoin integration is the same as running a Bitcoin node on chain.
Network integration
One key tech development allowing smart contracts on the BigFile to obtain the balances of Bitcoin addresses as well as directly send and receive bitcoin is inter-chain communication. As the BIG blockchain creates transactions for the Bitcoin blockchain, its nodes directly transmit the transaction to the nodes of the Bitcoin network, without any need for intermediaries that might censor them. BIG nodes also directly pull blocks from the Bitcoin network to maintain Bitcoin's current UTXO set, allowing cubes to query the balance of Bitcoin addresses and their UTXOs. Creating bitcoin transactions and querying UTXO sets are made available to canisters by the Bitcoin API.
Chain-key ECDSA
The real innovation behind Bitcoin integration is chain-key ECDSA signing — advanced threshold cryptography integrated with BIG. In short, chain-key ECDSA is a set of cryptographic protocols that allow BigFile nodes to cooperatively create ECDSA signatures, which can be used to sign bitcoin transactions, using a highly fault-tolerant, decentralized network that is resilient to attacks by malicious nodes. The secret key is never stored in one place, instead it is broken down into key shares held by BIG nodes that are re-shared periodically. When requested, nodes use their key shares to collectively sign BTC transactions without recreating the original secret key. This signing protocol assumes a threshold of nodes to be honest.
Code Bitcoin
Directly process bitcoin on the Bitcoin ledger using BIG smart contracts. Add bitcoin to your BIG Web3 services or create native Bitcoin DeFi.