Signed Attestations vs Push Logs: A Compliance-Focused Oracle Comparison

Immutable, portable verification: Each data point (e.g., KYC status, transaction hash) is signed by a trusted issuer's private key, creating a self-contained proof verifiable anywhere. This matters for cross-chain compliance and user-controlled data portability (e.g., EAS, Verax).

Off-chain data, on-chain proof: The attestation itself is stored on-chain (or on a decentralized storage layer like IPFS/Arweave), while the raw data can remain private. This matters for GDPR/CCPA compliance where storing PII directly on-chain is prohibited and for reducing gas costs.

Immutable, chronological ledger: All events (logins, transactions, state changes) are sequentially appended to an on-chain log (e.g., using a smart contract as a logger). This matters for financial auditing and regulatory reporting where a tamper-proof, time-stamped history of all actions is required (e.g., FATF Travel Rule compliance).

Streaming, event-driven data: Logs are emitted as real-time events, enabling immediate monitoring and alerting by compliance engines (e.g., Chainalysis, TRM Labs). This matters for AML transaction monitoring and suspicious activity detection where low-latency response is critical.

Attestations provide strong cryptographic proof of a specific claim but lack the full operational context. Push Logs provide the full contextual sequence of events but require trusting the log's integrity and emitter. Choose attestations for proof-of-status; choose logs for forensic analysis.

Attestations can be cheaper at scale for static claims, as verification is a one-time, off-chain computation. Push Logs incur recurring gas costs for every logged event, which can be prohibitive for high-throughput systems. For high-volume event logging (1,000+ events/day), consider attestations for summaries and logs for critical anomalies.

Non-repudiable Evidence: Each attestation is a signed, verifiable statement (e.g., EIP-712, EAS) that immutably links an entity to a claim. This provides court-admissible proof of action for KYC/AML checks or financial disclosures. Essential for protocols like Syndicate (ERC-7484) or Verax requiring tamper-proof records.

Selective Disclosure: Users can prove compliance (e.g., accredited status) without revealing underlying data via zero-knowledge proofs (ZK). This aligns with GDPR's data minimization principle. Frameworks like Sismo ZK Badges or Polygon ID use this for privacy-preserving KYC, reducing liability from storing sensitive PII.

Standardized Auditing: Structured event logs (e.g., AWS CloudTrail, Splunk) are the de facto standard for SOC 2, ISO 27001, and financial audits. They offer familiar query tools (SQL, Elasticsearch) for auditors. This is critical for TradFi integrations where regulators expect centralized, time-sequenced audit trails.

Operational Compliance: Enables real-time SIEM (Security Information & Event Management) integration for instant anomaly detection and reporting. Tools like Datadog or OpenZeppelin Defender can trigger alerts on suspicious transactions, which is mandatory for MiFID II trade surveillance and anti-fraud mandates.

Immediate, centralized audit trail: All state changes are streamed to a single, queryable log (e.g., Splunk, Datadog). This matters for SOC 2 compliance and real-time fraud detection, enabling instant alerts on suspicious transactions.

Standard enterprise tooling: Integrates directly with existing SIEM and monitoring stacks like Elasticsearch and AWS CloudWatch. This matters for teams with established DevOps workflows, reducing the compliance overhead for protocols like Aave or Compound.

Tamper-evident, portable records: Each log entry is a cryptographically signed EIP-712 attestation (e.g., using EAS). This matters for regulatory audits and on-chain dispute resolution, providing verifiable proof of state that can be independently validated by any third party.

No trusted central logger: The integrity of the log is secured by the signer's key, not a database. This matters for decentralized applications (dApps) and cross-chain compliance, where proofs must be verifiable without relying on a specific operator's infrastructure.