Trust and Proof Signals — The 61 Signals Explained
What Are Trust and Proof Signals?
Trust and Proof signals are the 61 data points that prove a business is who it claims to be and that its authority claims are accurate. Unlike Identity signals — which establish who the business is — Trust and Proof signals establish whether the business can be relied upon as an authoritative source.
These 61 signals carry the highest combined weight in AI recommendation decisions. A business that is correctly identified but has no trust signals will appear in AI answers. It will rarely be recommended. The recommendation threshold — Recommendable™ status — requires a strong trust signal profile, not just correct identity.
Trust signals are the bridge between Verifiable™ and Recommendable™. Every high-quality citation, every anchored proof file, every verified certification moves the business closer to the point where AI systems name it as the answer rather than one of many options.
Trust vs Proof — Two Distinct Mechanisms
Trust signals establish credibility through external validation — citations, reviews, directory presence, professional body membership. They say: other credible sources reference this business.
Proof signals establish immutability through cryptographic methods — SHA-256 fingerprinting and Bitcoin blockchain anchoring via OpenTimestamps. They say: these claims cannot have been fabricated after the fact.
Both are required. Trust without proof is self-reported credibility. Proof without trust is cryptographic verification of claims that no one has independently cited.
The Seven Trust and Proof Signal Groups
Group 1 — Certifications and Accreditations
8 signals| Signal | Description | Weight | File |
|---|---|---|---|
| trust.certification-count | Total number of active certifications held | High | authority.json |
| trust.certification-schema | All certifications in structured DefinedTerm schema with issuing body URL and validity period | Very High | authority.json |
| trust.certification-registry-url | Direct URL to certification entry in issuing body's public registry | Very High | authority.json |
| trust.iso-certification | ISO certification reference if applicable — ISO 9001, 27001, etc. | High | authority.json |
| trust.professional-qualification | Individual professional qualifications of key team members | Medium | authority.json |
| trust.accreditation-body | Accrediting body reference with URL for each active accreditation | High | authority.json |
| trust.certification-valid-until | Expiry date for each certification — expired certifications become negative signals | Medium | authority.json |
| trust.regulatory-approval | Regulatory body approval references for regulated sectors | Very High | authority.json |
Group 2 — Citations and External References
10 signals| Signal | Description | Weight | File |
|---|---|---|---|
| trust.citation-count | Total number of external citations — references from independent sources | High | authority.json |
| trust.citation-quality | Quality classification of citations — Tier 1 (media/academic), Tier 2 (industry), Tier 3 (peer) | Very High | authority.json |
| trust.tier1-citation-count | Number of Tier 1 citations from media outlets or academic publications | Very High | authority.json |
| trust.sector-publication-mention | References in sector-specific publications with article URL | High | authority.json |
| trust.academic-citation | Academic paper or research citations if applicable | Very High | authority.json |
| trust.press-mention-count | Number of press mentions with URLs | Medium | authority.json |
| trust.mention-consistency | Consistency of business description across all external mentions | High | authority.json |
| trust.government-reference | References in government or public sector publications | Very High | authority.json |
| trust.eu-institution-mention | References by EU institutions — high authority in EU markets | Very High | authority.json |
| trust.external-link-count | Count of external domains linking to the business website | Medium | authority.json |
Group 3 — Reviews and Testimonials
8 signals| Signal | Description | Weight | File |
|---|---|---|---|
| trust.aggregate-rating-schema | AggregateRating JSON-LD referencing external review platform with ratingValue and reviewCount | High | authority.json |
| trust.review-platform-url | Direct URL to review profile on Google, Trustpilot, or sector platform | High | authority.json |
| trust.review-count | Total number of verified reviews | Medium | authority.json |
| trust.average-rating | Average rating across all platforms — must be consistent with schema value | Medium | authority.json |
| trust.testimonial-schema | Named client testimonials in Review schema with client sector and attribution | Medium | authority.json |
| trust.testimonial-count | Number of named, attributed client testimonials | Low | authority.json |
| trust.video-testimonial | Video testimonial presence — higher trust weight than text | Medium | authority.json |
| trust.named-client-count | Number of named clients with consent to be publicly referenced | High | authority.json |
Group 4 — Case Studies and Outcomes
7 signals| Signal | Description | Weight | File |
|---|---|---|---|
| trust.case-study-count | Number of published case studies with structured outcome data | High | authority.json |
| trust.case-study-schema | Case studies in structured schema with client sector, problem, solution, and measurable outcome | Very High | authority.json |
| trust.measurable-outcome | Quantified result in each case study — percentage, time saved, revenue impact | Very High | authority.json |
| trust.client-sector-diversity | Range of sectors across case study portfolio — breadth of authority | Medium | authority.json |
| trust.case-study-client-size | Company size of case study clients — enterprise clients carry higher weight | Medium | authority.json |
| trust.case-study-geography | Geographic range of case study clients | Low | authority.json |
| trust.before-after-schema | Before/after state structured data with quantified delta | High | authority.json |
Group 5 — Awards and Professional Bodies
6 signals| Signal | Description | Weight | File |
|---|---|---|---|
| trust.award-count | Number of industry awards received | Medium | authority.json |
| trust.award-schema | Awards in structured schema with awarding body URL and year | Medium | authority.json |
| trust.professional-body-membership | Membership in recognised professional associations — FCCA, ACCA, IEEE, etc. | High | authority.json |
| trust.professional-body-registry-url | Direct URL to membership entry in professional body's public registry | Very High | authority.json |
| trust.industry-association | Membership in industry or trade associations | Medium | authority.json |
| trust.sector-directory-presence | Presence in authoritative sector-specific directories | High | authority.json |
Group 6 — Cryptographic Proof
12 signals| Signal | Description | Weight | File |
|---|---|---|---|
| proof.sha256-hash | SHA-256 fingerprint of each core authority document | High | ai-proof.json |
| proof.ots-status | OpenTimestamps anchor status — must be verified, never pending | Very High | ai-proof.json |
| proof.bitcoin-block | Bitcoin block number of OTS anchor for each document | High | ai-proof.json |
| proof.ots-file-url | Public URL to .ots proof file — must be accessible to any verifier | High | ai-proof.json |
| proof.proof-registry-url | URL to the public proof registry — ai-proof.json at domain root | Medium | ai-proof.json |
| proof.anchored-document-count | Number of documents with verified Bitcoin anchors | Medium | ai-proof.json |
| proof.innovation-registry | Anchored innovation registry entries with SHA-256 and block references | High | ai-proof.json |
| proof.manifest-hash | SHA-256 of the complete signal manifest — canonical infrastructure fingerprint | Medium | ai-proof.json |
| proof.external-audit-hash | SHA-256 of independent external audit document | Very High | ai-proof.json |
| proof.verification-badge | Third-party verification badge deployed with machine-readable JSON-LD | Very High | authority.json |
| proof.verification-body-url | URL to the verifying body — eu-ai-audit.eu for ADI™ clients | High | authority.json |
| proof.verification-date | Date of most recent independent verification | Medium | authority.json |
Group 7 — Governance and Transparency
10 signals| Signal | Description | Weight | File |
|---|---|---|---|
| trust.hitl-protocol | Human-in-the-Loop governance protocol documented and machine-readable | High | governance.json |
| trust.eu-ai-act-declaration | EU AI Act readiness declaration — supports readiness, never certifies | High | governance.json |
| trust.gdpr-declaration | GDPR compliance posture declaration with legal basis references | Medium | governance.json |
| trust.algorithmic-transparency | Declaration of AI tools used in business operations and governance | Medium | governance.json |
| trust.editorial-standards | Editorial standards declaration for content authorship and accuracy | Medium | policy.json |
| trust.content-authorship | Author attribution for all published content — Person schema | Medium | policy.json |
| trust.data-processing-declaration | Machine-readable data processing activities declaration | Low | policy.json |
| trust.ai-usage-declaration | Explicit declaration of AI usage in products and services | Medium | governance.json |
| trust.epistemic-discipline | Declaration of claims standards — what the business will and will not claim | Medium | governance.json |
| trust.trust-score | Composite trust score published in trust-state.json — updated quarterly | Low | trust-state.json |
The Highest-Weight Individual Signals
These seven signals carry the highest individual weight and should be prioritised when building the trust layer:
- proof.verification-badge — independent expert verification — highest single signal
- trust.certification-registry-url — enables AI to verify certification directly
- trust.case-study-schema with measurable-outcome — proves real-world authority
- trust.tier1-citation-count — media or academic citations carry maximum weight
- trust.professional-body-registry-url — enables AI to verify membership directly
- proof.ots-status verified — cryptographic proof of claim existence
- trust.eu-ai-act-declaration — governance posture signal — rising in weight
The Epistemic Discipline Rule — Universal Across All Trust Signals
Every trust and proof signal must follow the three-tier epistemic discipline: self_declared / publicly_verifiable / independently_certified. Claims must be graded accurately — overclaiming damages credibility with AI systems that verify independently. The canonical phrase is "supports readiness" — never "satisfies," "certifies," or "compliant." See: Innovation Registry →
Frequently Asked Questions
What are Trust and Proof signals?
Trust and Proof signals are the 61 data points that prove a business is who it claims to be and that its claims are accurate. They include certifications, external citations, case study schema, cryptographic proof files, and governance declarations. They carry the highest combined weight in AI recommendation decisions.
Why do Trust signals have the highest weight?
AI systems weight Trust and Proof signals highest because they represent external, independently verifiable evidence — not self-declared claims. A business with strong citation networks, verified certifications, and cryptographic proof is treated as a reliable source. Reliability translates directly to recommendation frequency.
What is the difference between Trust signals and Proof signals?
Trust signals establish credibility through external validation — citations, reviews, directory presence. Proof signals establish immutability through cryptographic methods — SHA-256 fingerprinting and Bitcoin anchoring. Both are required for maximum authority.
How does SHA-256 proof work as an AI signal?
A SHA-256 hash uniquely fingerprints a document. When published in ai-proof.json alongside an OpenTimestamps anchor to the Bitcoin blockchain, it allows any AI system to verify the document existed before the Bitcoin block was mined and has not been altered since.
Which Trust signal has the highest individual weight?
Third-party verification — specifically the eu-ai-audit.eu verification badge with machine-readable JSON-LD — has the highest individual weight. It represents independent expert assessment and is the strongest single trust signal in the ADI™ framework.