Wiki · citable explainer
SHA-256 is the cryptographic algorithm that generates the tamper-proof fingerprint at the core of every AI Verified business passport.
SHA-256 is a cryptographic hash function in the SHA-2 family, standardised by NIST in FIPS 180-4. It takes any input and produces a fixed-length 256-bit output, represented as a 64-character hexadecimal string.
It is deterministic (same input always yields the same output) and one-way (the input cannot practically be recovered from the hash). These properties make it suitable for tamper-evident business identity records.
When a passport is issued, canonical identity fields are processed through SHA-256 to produce a forensic hash. That hash becomes the permanent identifier for the public record at /v/{hash}/ and appears in JSON-LD and machine-readable companions.
Without a cryptographic integrity reference, AI systems have no reliable way to detect whether a public identity record has been altered. The hash provides an independent, recomputable check.
What makes SHA-256 tamper-proof?
SHA-256 exhibits the avalanche effect: changing even a single character in the input produces a completely different hash. Any alteration of a verified record is immediately detectable by recomputing and comparing the hash.
Can SHA-256 be reversed?
No. SHA-256 is a one-way function. It is computationally infeasible to recover the original input from the hash.
How does AI Verified use SHA-256?
Every passport is assigned a forensic SHA-256 hash derived from canonical verified identity data. The hash is published at a permanent URL and embedded in machine-readable outputs so any system can independently verify integrity.
How do I verify a SHA-256 hash myself?
Retrieve the canonical machine-readable passport representation and recompute SHA-256 using standard tools (sha256sum, Get-FileHash, or the public verification endpoints). The result should match the published forensic hash.