Verify a record

Every decision SANSAR makes is emitted as a signed record. Anyone holding one can verify it independently — no SANSAR server involved.

Verification is pure cryptography: check the signature against the published key, then check the record's place in the chain. This is what your auditor gets, for every agent action.

What's in a record

{
  "alg": "Ed25519",
  "record": {
    "id": "SANSAR://v1/DEC-20260704-091500",
    "action": "refund",
    "verdict": "allow",
    "agent": "billing-bot",
    "ts": "2026-07-04T09:15:00Z"
  },
  "sig": "base64( Ed25519 signature over the canonical record )",
  "prev": "hash of the previous record  // Merkle chaining"
}

The record is canonicalised, hashed (SHA-256), and signed with an Ed25519 key held on an HSM. Each record references the previous one, so the whole log is tamper-evident — you cannot alter or remove a record without breaking the chain.

How to verify

1. Take the record and its detached signature.
2. Fetch the signer's public key (published by the deployment; sovereign deployments hold their own keys).
3. Verify the Ed25519 signature over the canonical record bytes.
4. Check that prev matches the hash of the preceding record to confirm chain position.

Browser · WebCrypto

const key = await crypto.subtle.importKey(
  "jwk", publicJwk, { name: "Ed25519" }, false, ["verify"]);

const ok = await crypto.subtle.verify(
  "Ed25519", key, signatureBytes, canonicalRecordBytes);

console.log(ok ? "ed25519 VALID" : "VERIFICATION FAILED");

Command line · OpenSSL

openssl pkeyutl -verify -pubin -inkey pub.pem \
  -rawin -in record.canonical -sigfile record.sig

Verified locally, no server involved. The signature either checks out or it doesn't — there's nothing to trust but the math.