Introduction to OLA

OLA is an infrastructure focused on cross-chain trusted interactions, providing inter-chain zero-knowledge proofs for the Bitcoin ecosystem.

OLA is an infrastructure focused on cross-chain trusted interactions, providing inter-chain zero-knowledge proofs for the Bitcoin ecosystem.

Traditional BTC cross-chain bridges often rely on multi-signature custody or centralized intermediaries, which place additional trust assumptions on the safety of user funds, usually controlled by a single entity or a majority of entities. This model presents centralized risks and deviates from the decentralized spirit of Bitcoin. In contrast, OLA aims to minimize reliance on third parties for cross-chain bridges through cryptographic methods and decentralized mechanisms.

With the gradual improvement of the BitVM2 protocol engineering practice, the Trust-minimized Bridge built on BitVM2 has become an important infrastructure for various Bitcoin projects. The construction of the Bitcoin Trust-minimized Bridge requires several core foundational modules:

• Block Header ZKP (Zero-Knowledge Proof) generation and management

• Chain state synchronization and state proofs

• Supervised and decentralized verifiers for proofs

• Efficient and lightweight proof aggregation and submission

OLA concentrates on building a full-chain Block Header ZKP generation and management platform, providing verifiable chain state proofs for different projects' Trust-minimized Bridges to ensure the credibility of state synchronization among multiple chains. Its goal is to establish an interaction channel with minimal trust assumptions between Bitcoin and other blockchains, realizing cross-chain bridging infrastructure without custodians. Through the chain state proofs provided by OLA, cross-chain bridges based on the BitVM2 protocol can verify state changes on the Bitcoin main chain and target chains without trusting any intermediary, executing cross-chain operations like Peg-In (anchoring deposits) and Peg-Out (redeeming withdrawals) safely. It's noteworthy that this design enables the cross-chain flow of Bitcoin assets to no longer depend on centralized custody or federated multi-signatures but relies on zero-knowledge proofs and decentralized verification networks for safety. OLA hopes to become the native cross-chain connection base for Bitcoin, extending its security to a multi-chain environment and lowering the trust cost in cross-chain interactions.

OLA Technical Architecture and Module Description

The OLA system comprises several modules that work in coordination, each performing its role to achieve the generation, verification, and submission of inter-chain state proofs. The main architectural modules include:

1) Block Header ZKP Generation Module: This module is responsible for periodically collecting Bitcoin block headers and generating zero-knowledge proofs (ZKPs) for them. The ZKPs attest to the state of the Bitcoin chain at specific heights without revealing the actual block header data. This ensures that the state snapshot is provably derived from the Bitcoin main chain.

2) Chain State Synchronization Module: Different blockchains have their own state transition models. This module tracks the state changes on the target chain and synchronizes them with the corresponding Bitcoin chain state at the same height through ZKPs. For instance, if a user deposits ETH into a cross-chain bridge to perform a Peg-In operation, this deposit will be reflected as a state change on the Ethereum chain, which the Chain State Synchronization Module detects and handles. At the same time, the module fetches Block Header ZKPs for the same height from the Bitcoin chain to attest to the Bitcoin state at that specific time period.

3) Proof Verifier Network: Multiple decentralized verifiers participate in verifying the validity of ZKPs and performing lightweight computations on state transitions. They ensure that the state proofs used for cross-chain operations are indeed generated by the ZKP Generation Module and have not been tampered with. This network serves as a final checkpoint for cross-chain state updates, preventing malicious actors from forging proofs to manipulate funds.

4) Proof Aggregation and Submission Module: As the number of verifiers increases, the computational and storage requirements for verifying ZKPs and performing state synchronization will become more demanding. This module aggregates proofs from different verifiers and submits them to the target chain in a batched and efficient manner. This reduces the computational burden on individual verifiers and optimizes the throughput of cross-chain operations.

5) Supervisor Network and Challenger Network: To minimize the risk of a single party acting dishonestly, there are two additional networks: the Supervisor Network monitors the overall operation of the cross-chain bridge and detects any anomalies or potential issues. The Challenger Network can actively challenge any suspicious behavior and provide evidence to the supervisor network for making final decisions. Together, they form a decentralized supervision and dispute resolution mechanism to ensure the honest execution of cross-chain transactions.

The above modules work together to achieve a cross-chain bridge infrastructure that is minimally trusted and capable of verifying states across multiple blockchains. OLA extends Bitcoin's security model to inter-chain interactions: funds are hosted by smart contracts and BitVM2 scripts, combined with the supervision of multiple verifiers, allowing the cross-chain bridge to operate securely with minimal trust assumptions (such as 1-of-N participants being honest).

Overview of OLA Technical Process

To ensure the credible synchronization of multi-chain states, OLA has built a