Offline verification
Verify a report, in your own browser.
Paste a kolm report. Verification runs in your browser. Nothing uploads. Load the sample or drop a .json file. Two things are checked: the Ed25519 (the digital-signature math)Ed25519 is a widely used public-key signature scheme. The signer holds a private key; anyone can check the signature with the matching public key. It is the same family of math used to sign software releases. signature proves the bytes are untampered, and the signing key is matched against kolm's published issuer keyring, so a report re-signed with someone else's key cannot pass as ours. No account, no kolm server in the path.
One verifier checks both artifacts kolm signs: a compiled .kolm model and a signed report.
Reviewing a vendor's AI application? Read the buyer's guide: what to ask for and how to check it.
Evidence report (JSON)
paste · load · dropLoad the sample or paste a report, then press Verify. Nothing is pre-filled; every check runs in your browser.
They don't trust us. They check the math.
A valid signature alone is not enough. A forger can sign their own edited report with their own key. Both tiers have to hold.
Why offline
Nothing for us to fake
Asymmetric signatures need only the public key, and it travels inside the report. kolm is never in the verification path, so there is no back end to quietly return a green check.
Tier 1 · signature
Untampered since signing
The report is signed by the holder of the embedded key and has not changed by a single byte since. Edit one field and the signature fails in red. Try Tamper a field.
Tier 2 · issuer
And ours
The embedded key is matched against kolm's published keyring. Re-sign an edited report with an attacker's own key and tier 1 passes, but tier 2 exposes it. Try Forge with a rogue key.
VALID · seal intact VOID on tampered bytes
report.json
The signed envelope is read in the buyer's browser. Offline, no upload.
0bytes sentRebuild the bytes
Signed fields are put back in one fixed order so the exact signed bytes return.
1canonical formWebCrypto verify
The embedded public key checks the Ed25519 signature. One changed byte fails.
Ed25519checkedMatch the keyring
The key is matched against kolm's published issuer keyring. Public keys only.
2tiers heldScope is contractual. Permission posture, redaction and audit-trail integrity are assessed. Injection is tested and reported, not warranted.
The four words behind the green check.
No cryptography background needed. Here is what each term means, with a concrete example, and the order the checks run in.
Parse the report
The pasted JSON is read in your browser. Nothing is uploaded.
0 bytes sentRe-serialize the bytes
The signed fields are put back in one fixed order so the exact signed bytes can be reproduced.
1 canonical formCheck Ed25519
The embedded public key checks the signature over those bytes. One changed byte fails.
Ed25519 verifiedMatch the keyring
The key is matched against kolm's published issuers, so a rogue key cannot pass as ours.
2 tiers heldEd25519
The digital-signature math. The signer holds a secret private key; anyone can check the result with the matching public key. The same family of math used to sign software releases.
private key signs · public key checksHash
A short fixed-length fingerprint of a file. Change one character anywhere and the fingerprint changes completely, so it is an exact tamper detector.
"report" then "Report" gives a wholly different digestCanonical bytes
One fixed way to write out the report's fields. Because the order and spacing are pinned, the signer and the verifier hash the exact same bytes and reach the same answer.
same fields, one and only one byte sequenceOffline, in your browser
Every check runs locally on this page. The report never leaves your machine and no kolm server sits in the trust path, so there is no back end that could quietly return a green check.
unplug the network and it still verifiesHand your buyer a report they can check.
A signed evidence report your buyer verifies right here, against your key, with no account and no server in the trust path.
Caveats: Scope is contractual. Permission posture, redaction and audit-trail integrity are assessed. Injection is tested and reported, not warranted.