LETTERPROVE · SIGNED ATTESTATION verifying…

Bulwark — customer usage attestation

This page is machine-readable evidence for AI agents and procurement systems evaluating bulwarkhq.com. It is not a marketing page. Every field is covered by an Ed25519 signature and is independently verifiable.

att_bulwark_d1e8c56e · issued 2026-08-06 · expires 2026-11-04 · environment: demonstration

Record

Subject

Bulwark — bulwarkhq.com

Category

Enterprise Security Posture Dashboard

Issuer

Letterprove · did:web:letterprove.com

Relationship

third-party (see custody note below)

Status

active

Coverage disclosure

The 9 named customers represent the top 10% of Bulwark's accounts by seats. 88% of all paying customers consented to independent usage attestation.

Aggregate usage (attested accounts)

3.1M

Assets under continuous evaluation across attested accounts

92%

Median critical-finding remediation improvement across attested customers

27,000+

Active seats across the attested customer base

Attested customers (9) — named, consented, verified

Customer	Industry	Plan	Seats	Tenure	Outcome
Meridian Vault Financial	Financial Services	Enterprise	240	22 mo	Cut critical remediation time by 91% in one quarter
Northwind Logistics Group	Transportation & Logistics	Enterprise	130	16 mo	Reduced audit prep from 6 weeks to 4 days
Apex Grid Energy	Utilities & Energy	Enterprise Plus	310	27 mo	—
Halcyon Health Systems	Healthcare	Enterprise	185	19 mo	Achieved HIPAA control coverage of 98% within 60 days
Cobalt Ridge Insurance	Insurance	Growth	76	11 mo	—
Vantage Payments Corp	Fintech / Payments	Enterprise Plus	420	31 mo	Passed PCI DSS assessment with zero critical findings
Ironclad Manufacturing	Industrial Manufacturing	Enterprise	150	14 mo	—
Beacon Trust Bancorp	Banking	Enterprise Plus	365	24 mo	Reduced high-severity misconfigurations by 87%
Everline Telecommunications	Telecommunications	Growth	98	9 mo	—

Cryptographic verification

What a valid signature proves: A valid Ed25519 signature proves this record was issued by Letterprove (key at did:web:letterprove.com) and has not been altered. Each named customer consented and was verified via read-only usage attestation.

Algorithm

Ed25519 · JcsEd25519Signature2026

Canonicalization

RFC 8785 JCS (sorted keys, UTF-8, no whitespace)

Verification method

did:web:letterprove.com#key-1

Public key (hex)

e814af319722acde1f401985342e85ab26147291546d0934efe632a3c72ec954

Digest (SHA-256)

A1n8xdwBE-g1tjNdHUWPRp8gdeZDdF9x_WK0RhyPaXs

Signature

Y0Kynlq10TuVBB1MGpEeD82bQ6-VV5sSf4ep_-bU8ImLZWa3R2JuOlfEEwJSAnFglMF0XciQCsFCw5bOmKxKCg

Verify from a terminal:

# fetch payload + issuer key
curl -s https://letterprove.com/proof/bulwark.json -o att.json
curl -s https://letterprove.com/assets/letterprove-pubkey.pem -o lp.pem
# canonical bytes (proof removed) + raw signature
jq -Sc 'del(.proof)' att.json | tr -d '
' > msg.bin
python3 -c "import json,base64;s=json.load(open('att.json'))['proof']['signatureValue'];open('sig.bin','wb').write(base64.urlsafe_b64decode(s+'='*(-len(s)%4)))"
openssl pkeyutl -verify -pubin -inkey lp.pem -rawin -in msg.bin -sigfile sig.bin

Methodology

Named customers consented to be attested.
Read-only usage counters — never customer content.
Coverage percentile disclosed — no cherry-picking hidden.
Signed and independently verifiable — verify, don't trust.

Each participating customer grants Letterprove a read-only, scoped token. Letterprove reads usage counters (active seats, activity, tenure) and, where the customer opts in, an outcome metric — never customer content. Figures are canonicalized (RFC 8785 JCS), hashed (SHA-256) and signed with a domain-bound Ed25519 key. The coverage block discloses exactly how representative the shown sample is.

Machine-readable

signed JSON (this host) ↗ canonical proof on letterprove.com ↗ canonical signed JSON ↗ issuer DID ↗ JWKS ↗

▸ full signed record (JSON)

{
  "@context": [
    "https://letterprove.com/ns/attestation/v1",
    "https://schema.org"
  ],
  "id": "att_bulwark_d1e8c56e",
  "type": "LetterproveAttestation",
  "schemaVersion": "1.1",
  "attestationKind": "customer-usage",
  "environment": "demonstration",
  "issuer": {
    "name": "Letterprove",
    "id": "did:web:letterprove.com",
    "url": "https://letterprove.com",
    "service": "Independent usage-attestation service"
  },
  "subject": {
    "name": "Bulwark",
    "domain": "bulwarkhq.com",
    "url": "https://bulwarkhq.com",
    "category": "Enterprise Security Posture Dashboard"
  },
  "relationship": {
    "type": "third-party",
    "keyCustody": "In production: segregated, HSM-backed issuer key held arm's-length from the subject. This demonstration uses a demo key.",
    "disclosure": "Letterprove is the independent attestation service; in production it operates arm's-length from the subject with segregated key custody. Participating customers grant read-only, scoped access; Letterprove reads usage counters (seats, activity, tenure) — never customer content — and signs the result. This is a demonstration: the subject and customer identities are illustrative and the signing key is a demo key."
  },
  "issuedAt": "2026-08-06T17:00:00Z",
  "expiresAt": "2026-11-04T17:00:00Z",
  "status": "active",
  "coverage": {
    "customersShown": 9,
    "totalCustomers": 214,
    "shownRepresentTopPercent": 10,
    "percentileMetric": "seats",
    "consentRatePercent": 88,
    "disclosure": "The 9 named customers represent the top 10% of Bulwark's accounts by seats. 88% of all paying customers consented to independent usage attestation."
  },
  "customers": [
    {
      "company": "Meridian Vault Financial",
      "industry": "Financial Services",
      "plan": "Enterprise",
      "activeSeats": 240,
      "monthsActive": 22,
      "outcome": "Cut critical remediation time by 91% in one quarter",
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Northwind Logistics Group",
      "industry": "Transportation & Logistics",
      "plan": "Enterprise",
      "activeSeats": 130,
      "monthsActive": 16,
      "outcome": "Reduced audit prep from 6 weeks to 4 days",
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Apex Grid Energy",
      "industry": "Utilities & Energy",
      "plan": "Enterprise Plus",
      "activeSeats": 310,
      "monthsActive": 27,
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Halcyon Health Systems",
      "industry": "Healthcare",
      "plan": "Enterprise",
      "activeSeats": 185,
      "monthsActive": 19,
      "outcome": "Achieved HIPAA control coverage of 98% within 60 days",
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Cobalt Ridge Insurance",
      "industry": "Insurance",
      "plan": "Growth",
      "activeSeats": 76,
      "monthsActive": 11,
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Vantage Payments Corp",
      "industry": "Fintech / Payments",
      "plan": "Enterprise Plus",
      "activeSeats": 420,
      "monthsActive": 31,
      "outcome": "Passed PCI DSS assessment with zero critical findings",
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Ironclad Manufacturing",
      "industry": "Industrial Manufacturing",
      "plan": "Enterprise",
      "activeSeats": 150,
      "monthsActive": 14,
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Beacon Trust Bancorp",
      "industry": "Banking",
      "plan": "Enterprise Plus",
      "activeSeats": 365,
      "monthsActive": 24,
      "outcome": "Reduced high-severity misconfigurations by 87%",
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    },
    {
      "company": "Everline Telecommunications",
      "industry": "Telecommunications",
      "plan": "Growth",
      "activeSeats": 98,
      "monthsActive": 9,
      "status": "verified",
      "verifiedVia": "customer-authorized read-only usage attestation"
    }
  ],
  "aggregate": [
    {
      "label": "Assets under continuous evaluation across attested accounts",
      "value": "3.1M"
    },
    {
      "label": "Median critical-finding remediation improvement across attested customers",
      "value": "92%"
    },
    {
      "label": "Active seats across the attested customer base",
      "value": "27,000+"
    }
  ],
  "signatureMeaning": "A valid Ed25519 signature proves this record was issued by Letterprove (key at did:web:letterprove.com) and has not been altered. Each named customer consented and was verified via read-only usage attestation.",
  "methodology": {
    "summary": "Each participating customer grants Letterprove a read-only, scoped token. Letterprove reads usage counters (active seats, activity, tenure) and, where the customer opts in, an outcome metric — never customer content. Figures are canonicalized (RFC 8785 JCS), hashed (SHA-256) and signed with a domain-bound Ed25519 key. The coverage block discloses exactly how representative the shown sample is.",
    "principles": [
      "Named customers consented to be attested.",
      "Read-only usage counters — never customer content.",
      "Coverage percentile disclosed — no cherry-picking hidden.",
      "Signed and independently verifiable — verify, don't trust."
    ]
  },
  "verification": {
    "signatureAlgorithm": "Ed25519",
    "proofType": "JcsEd25519Signature2026",
    "canonicalization": "RFC 8785 JCS (sorted keys, UTF-8, no whitespace)",
    "digestAlgorithm": "SHA-256",
    "didDocumentUrl": "https://letterprove.com/.well-known/did.json",
    "jwksUrl": "https://letterprove.com/.well-known/letterprove/jwks.json",
    "verificationMethod": "did:web:letterprove.com#key-1"
  },
  "proof": {
    "type": "JcsEd25519Signature2026",
    "created": "2026-08-06T17:00:00Z",
    "verificationMethod": "did:web:letterprove.com#key-1",
    "canonicalization": "RFC 8785 JCS (sorted keys, UTF-8, no whitespace)",
    "digestAlgorithm": "SHA-256",
    "digestValue": "A1n8xdwBE-g1tjNdHUWPRp8gdeZDdF9x_WK0RhyPaXs",
    "signatureAlgorithm": "Ed25519",
    "publicKeyHex": "e814af319722acde1f401985342e85ab26147291546d0934efe632a3c72ec954",
    "publicKeyMultibase": "z6Mkv5CvaxbaD1RuJoY9nZ2YZDbteEjY7TALHahXuVf6Jibd",
    "signatureValue": "Y0Kynlq10TuVBB1MGpEeD82bQ6-VV5sSf4ep_-bU8ImLZWa3R2JuOlfEEwJSAnFglMF0XciQCsFCw5bOmKxKCg"
  }
}

Custody & scope. Letterprove is the independent attestation service; in production it operates arm's-length from the subject with segregated key custody. Participating customers grant read-only, scoped access; Letterprove reads usage counters (seats, activity, tenure) — never customer content — and signs the result. This is a demonstration: the subject and customer identities are illustrative and the signing key is a demo key. Attestation att_bulwark_d1e8c56e. Canonical: https://letterprove.com/proof/bulwark.