Trust Principles of Nubit

Nubit’s security model is founded on a set of critical assumptions, each playing a vital role in maintaining the network’s integrity and functionality:

Majority of Honest Validators

The integrity of the network hinges on the majority of validators being trustworthy. This ensures reliable bridge operations and block validity. Nubit can use external PoS security providers like BabylonChain to establish an initial economic security threshold from Bitcoin staking.

Effective DAS

Light clients, alongside Full Nodes, perform DAS to ensure all data is accessible for validation despite light clients not storing the full data. If a sufficient number of light nodes successfully sample a full node, DAS ensures that the data is fully available. Note that a single light node cannot be certain of the full availability of the data, as it queries only a small portion of the encoded data, therefore DAS still requires a sufficiently large group of light nodes.

1-to-N Full Node Security Model

Through Bitcoin anchoring, Nubit drastically reduces the withdrawal timeframe to less than four hours from weeks. Additionally, These checkpoints provide an extra layer of security guarantee, s.t. the integrity of data stored in a full storage node can be determined based on these checkpoints. Even in the event of a complete Nubit network collapse, nodes can still perform data restoration using full nodes and checkpoints submitted on Bitcoin.

Formal Verification

Previous incidents of security breaches within the blockchain domain underscore the importance of integrating both theoretical and practical security measures. Consequently, for critical infrastructures such as the bridge and the consensus algorithm, the Nubit team, along with external audit entities, will employ formal verification to rigorously evaluate the security attributes of the system, thereby ensuring the integrity of the security assumptions by demonstrating the improbability of their violation.