3.2 Components

Biop uses some components to realize the Optimistic rollup protocol, PoS and the interaction between protocols. Biop uses technologies such as BVM, smart contract, and Merkle Tree to complete the computing, state storage, query, and verification of Bitcoin protocols, and to ensure that the state of the protocols can be traceable, verifiable and immutable.

3.2.1 BVM

BVM (Bitcoin Virtual Machine), is the core component of Biop Chain. BVM is responsible for the deployment, execution, query and verification of smart contracts. BVM is an important extension to Bitcoin network by Biop. As a Turing Complete virtual machine, the computing of Bitcoin's BRC-20 and many other protocols will eventually be completed on BVM. BVM is EVM Equivalence — complete alignment with the Ethereum Virtual Machine specification, which means that many developers, decentralized applications, and users of Ethereum ecosystem can seamlessly connect to Biop, laying the foundation for the rapid expansion of Biop ecosystem.

3.2.2 BiopOS

BiopOS is the core implementation of Bitcoin L2, which implements and executes the Optimistic rollup protocol and PoS consensus algorithm, including the generation of Biop block, management of Sequencer and Validator, management of transaction fee, and the interaction with L1(Bitcoin). To save transaction fee, Biop block state data will be stored to Bitcoin as witness.

3.2.3 Ledger Syncer

Ledger Syncer is responsible for interacting with Bitcoin node, parsing various protocol ledgers such as BTC ledgers, inscriptions ledgers, and BRC-20 ledgers from Bitcoin block to Biop Chain, as the input for the computing engine.

3.2.4 Computing Engine

Due to the limitation of Bitcoin's scripting system, Bitcoin does not support Turing Complete virtual machine, the computing of new Bitcoin protocols such as BRC-20 relies on centralized servers off Bitcoin network to complete, and various risks such as censorship are very high. Biop will complete the computing of the new Bitcoin protocols through the Computing Engine, move the computing which cannot be completed by Bitcoin script, and compute: the transfer of inscriptions, Ordinals, the state of BRC-20 and other protocols, etc. Make the new Bitcoin protocols supported by Biop decentralized infrastructure, and be truly decentralized, censorship resistance, trustable, traceable, immutable and verifiable.

3.2.4.1 Shadow Contract

Shadow contract is the smart contract corresponding to BRC-20 and other protocols mapped on the Biop Chain. The execution and verification of shadow contract is guaranteed through BVM. With the shadow contract, developers and users can verify the state of the new Bitcoin protocols like invoking the smart contract from Ethereum, which make the new Bitcoin protocols computing, query and verification fully decentralized and trustable.

3.2.4.2 Bitcoin Contract

For Bitcoin have better computing capability, Biop will support smart contract inscribed on Bitcoin by inscriptions or other methods. The smart contract is saved on Bitcoin, executed and verified in Biop's BVM, which will make Bitcoin have virtual machine to execute smart contract and computing capability like many chains such as Ethereum. Then finally the Bitcoin will have the technical infrastructure: BVM to build complex decentralized applications like DEX, DeFi, GameFi, etc.

3.2.4.3 Merkle Tree

Bitcoin uses Transactions Merkle Tree to save all the transactions of block. Similar to the Transactions Merkle Tree of Bitcoin, Biop will use more Merkle Trees: State Merkle tree, Ordinals Merkle tree, Transaction Merkle tree, Receipt Merkle tree, to save the computed results from Computing Engine, used for decentralized query and verification.

3.2.5 Router Contract

Router Contract is a smart contract which stores the metadata of all Bitcoin protocols, and provides query and verification services for BRC-20 and other protocols externally. Router Contract matches user's request to the corresponding shadow contract or Merkle Tree to complete the final query or verification. In the future, Biop DAO will decide if charge BIOP token for protocol fee and how to use the fee, such as distribution to Sequencer or burn, etc.

3.2.6 Merkle Proof

For new Bitcoin protocols such as BRC-20, Biop computing engine will compute and save the Merkle Proof to verify the new protocol state. This is very important, the state of all new protocols is verifiable, and the verification is based on Biop's decentralized nodes, based on immutable Merkle Tree technology.