Random leader selection, object ownership, slashing, and parallel execution make collusion hard and risky.

Sui prevents validator collusion through:

• Byzantine fault tolerance: Tolerates up to 1/3 malicious validators.

• Deterministic execution: Makes manipulation detectable.

• Decentralized consensus: No single validator controls ordering.

• Stake-based incentives: Validators risk losing rewards for misbehavior.

These mechanisms discourage censorship and manipulation.

How Sui Prevents Validator Censorship and Manipulation

Uses BFT consensus (Narwhal + Bullshark) that tolerates up to 1/3 malicious validators.

Most transactions run object-centric and in parallel, avoiding consensus bottlenecks and censorship.

Transactions are ordered deterministically by object dependencies, preventing reordering or front-running.

Validators are rotated and governed to remove bad actors over time.

Validator actions are publicly auditable, enabling detection of censorship attempts.

Result: Sui’s design limits validator power and ensures censorship-resistant, fair transaction processing.

Sui prevents validator collusion and transaction manipulation through its object-centric, parallel execution model combined with a consensus protocol that requires quorum agreement. Transactions operate on specific objects, and only validators responsible for those objects can process them, reducing the chance for a single validator to censor unrelated transactions. The system enforces conflict detection: if two transactions try to modify the same object simultaneously, only one can succeed, and the network resolves order fairly based on consensus. Additionally, validators are incentivized economically to behave honestly, and misbehavior can be detected and penalized. This combination of object ownership, parallel execution, and quorum-based consensus minimizes the risk of censorship or manipulation.

Read more here: Sui Validator Security.