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© 2026 FONTEUM RESEARCH · DATA SNAPSHOT MAY 8, 2026 · BUILT WITH CARE

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Trust → Integrity → Chain

Attestation chain head.

Every snapshot Fonteum publishes is SHA-256 hashed at write time and appended to a Certificate-Transparency-style log. The head of that log — the most recent attestation — is published below. Once the per-snapshot previous_link_hash backfill lands under §sprint3-attestation-chain, every row will additionally chain backwards to the prior row, making any tampering detectable by a single recomputation.

Current head

Chain bootstrap is in progress. The first attestations are being written; refresh in 5 minutes or watch /trust/integrity for the live attestation index.

Total attestations on file: 0

How the chain works

  1. Each upstream archive is downloaded, SHA-256 hashed, and written to snapshot_attestations with the source archive URL preserved verbatim.
  2. Each new row carries a previous_link_hashfield set to the prior row's content_hash (or all-zero for the first row in a source family). Tampering with any historical row breaks every downstream link.
  3. A periodic STH (Signed Tree Head) seals the chain head with Fonteum's chain-signing public key. Verifiers fetch the STH, walk the chain backwards, and confirm every link.
/verify — re-hash any attested snapshot →/trust/integrity — full attestation index →/docs/cache — 90-day source mirror →