Reputation Attestation

The attestation is mathematically tied to both the subject (the entity being evaluated) and the issuer (the attesting authority). This is achieved through digital signatures using asymmetric cryptography. The issuer signs a structured payload containing the subject's identifier and the reputation claim, creating a tamper-evident seal. Any subsequent modification to the attested data invalidates the signature, ensuring data integrity. This binding proves the issuer explicitly endorsed the specific claim at a specific time.

The core logic relies on a transitive trust model. A relying party (verifier) trusts the reputation claim not because it knows the subject, but because it trusts the attester. The attester's own authority score or public key is pre-established in a Web of Trust or a centralized Public Key Infrastructure. This decouples reputation assessment from direct interaction, enabling scalable trust in large, decentralized networks.

Attestations are not free-text reviews; they are machine-readable, structured data objects. They typically conform to standards like the W3C Verifiable Credentials data model. A claim includes:

• Subject: Decentralized Identifier of the entity.
• Property: The specific reputation metric (e.g., 'credit_score', 'uptime_percentage').
• Value: The attested data (e.g., '750', '99.99%'). This structure allows algorithms to parse and act on the reputation data without human interpretation.

A valid reputation attestation is cryptographically bound to a specific Decentralized Identifier or public key. It cannot be transferred or sold to another entity to artificially inflate their reputation. This is often enforced by requiring the subject to prove control of the underlying private key during verification. This property is essential for Sybil resistance, preventing attackers from reusing a single positive attestation across multiple fake identities.

Attestations carry explicit temporal constraints to prevent the indefinite propagation of stale trust. Key metadata fields include:

• Issuance Date: The timestamp of creation.
• Expiration Date: A mandatory field after which the attestation is cryptographically invalid.
• Revocation Status: A pointer to a revocation registry (often a distributed ledger or OCSP-style endpoint) that allows the issuer to invalidate the attestation before its expiry if the subject's behavior degrades.

Advanced attestation schemes support selective disclosure and zero-knowledge proofs. A subject can prove they possess an attestation with a specific property (e.g., 'credit score > 700') without revealing the exact value ('750') or the issuer's identity. This is implemented using cryptographic techniques like BBS+ signatures or zk-SNARKs, enabling privacy-preserving reputation verification where the verifier learns only the boolean outcome of a predicate, not the underlying sensitive data.

A trusted external data feed or computational service that bridges off-chain reputation data to on-chain smart contracts, enabling blockchain applications to react to real-world trust scores.

• Signs attestations with a known public key
• Aggregates multiple reputation signals into a single verifiable claim
• Critical for decentralized finance credit scoring
• Must maintain strict liveness and correctness guarantees

A non-transferable digital identity token representing commitments, credentials, and affiliations of an entity, forming the basis for a decentralized, non-financialized reputation system.

• Permanently bound to a specific blockchain address
• Cannot be sold or transferred between parties
• Encodes attestations from issuers directly into the token metadata
• Enables composable reputation across decentralized applications

A programmable penalty mechanism in proof-of-stake and reputation protocols that destroys a portion of staked assets or reputation score for provably malicious or negligent behavior.

• Creates cryptoeconomic security for attestation networks
• Attesters risk losing deposited collateral for false claims
• Parameters include penalty amount, challenge window, and dispute resolution
• Aligns economic incentives with truthful attestation behavior

A privacy-preserving protocol allowing a prover to demonstrate possession of a certain reputation score or credential without revealing the underlying data or specific score value.

• Uses zk-SNARKs or zk-STARKs for succinct proofs
• Enables threshold proofs: "score > X" without disclosing exact value
• Preserves confidentiality while maintaining verifiability
• Critical for compliance with data minimization principles