Guarantees and Properties

FastSet does away with global consensus and strict ordering, two cornerstones of traditional blockchain systems, yet it still manages to offer strong guarantees around consistency, safety, and trust.

This section explains what FastSet promises, how those promises are upheld, and why developers can confidently build on it.

Safety from double-spending

As stated in the previous section, FastSet prevents double-spending through its validator design and local state checking. If an actor issues two conflicting claims such as trying to spend the same tokens twice, validators will detect the conflict during validation.

Because each validator independently checks whether a claim is valid before signing it, conflicting claims cannot both reach quorum. Only one of the claims will gather enough validator support to be certified, while the other will be rejected or remain unfinalized.

This approach ensures that only one version of a conflicting action can become part of the global state, even without needing all validators to agree in advance or coordinate execution.

Quorum-based settlement

In FastSet, a claim is not considered settled just because it was received or validated by a single party. Settlement only happens when a claim gathers enough validator signatures to meet a quorum threshold. These signatures are bundled into a certificate, which proves that the claim has been accepted by a sufficient portion of the network.

This model makes it easy to distinguish between claims that are pending and those that are final. Any system or client can rely on a certified claim with confidence, without needing to verify the state of the entire network. The quorum size and validator set can also be configured to meet the trust or decentralization goals of a specific deployment.

No forks or reorganizations

FastSet’s design avoids the possibility of forks and chain reorganizations, issues that often arise in blockchain systems that rely on longest-chain rules or probabilistic finality.

Because FastSet does not operate on a chain of blocks, and because a claim becomes final once certified by a quorum, there is no risk of an already settled claim being reversed. There are no rollbacks or reorganizations of the system state. Once a claim is certified, it is final and immutable.

This adds a level of predictability and stability that is particularly important in high-stakes applications like payments, AI verification, or data access control.

Verifiability and auditability

Every settled claim in FastSet includes a certificate, which is simply a cryptographic proof that the claim was accepted by a quorum of validators. These certificates can be verified by any third party without needing access to the full validator set or network history.

This gives developers and system designers a reliable way to track and audit changes, verify outcomes, and build systems that can interface with FastSet as a source of truth. Whether you are proving a payment happened, confirming an attestation, or recording the result of a verifiable computation, certificates provide tamper-proof, portable evidence.

In summary

Although FastSet gives up traditional consensus and global ordering, it maintains clear, strong guarantees. It ensures that honest validators eventually converge to the same state, prevents double-spending, enforces finality through certificates, and eliminates the possibility of forks or rollbacks. All while enabling fast, parallel processing and cryptographic verifiability.

These properties make FastSet a powerful protocol for modern decentralized applications, especially those that demand scale, reliability, and trust without consensus overhead.