Glossary

Hash chain

A sequence of records where each one cryptographically includes the hash of the previous.

category ▸ Data & Provenance

audit/verify
#101hash ✓#102hash ✓#103hash ✓#104hash ✓#105hash ✓
head 0x9f3a…c1ok: true
verifyChain ▸ chained SHA-256 · signed receipts
What it means

Hash chain, in plain language.

A hash chain links records so that each entry carries a fingerprint (a cryptographic hash) of the entry before it. Because changing any record changes its hash — and therefore every record that follows — the chain makes tampering self-evident: recompute the hashes and the first mismatch points exactly to where history was altered.

It is the simplest reliable construction for tamper-evidence and the core idea behind both audit ledgers and blockchains. The chain does not prevent edits; it makes them impossible to hide.

In Cortex

How Cortex implements it.

This term isn't abstract here — it maps to a real capability in the runtime. Here is exactly how Cortex enforces or relates to it.

Data & Provenance

Cortex computes a stable, key-sorted canonical form of each event, hashes it, and links it to the previous record's hash, with a monotonic per-tenant sequence number. The verifyChain function recomputes the chain and returns a verdict with the broken sequence if any record was inserted, edited, deleted, or reordered.

The same primitive secures solution packs: a pack's contents are hashed and signed, so any tamper breaks hashOk and any wrong key breaks signatureOk.

See Hash chain enforced, not just defined.

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Hash chain — definition | Cortex AI OS