Ed25519 public key, attestation verification

Current public key

Rotation history

MEOK rotates its attestation key every 90 days. The rotation event is signed by the outgoing key, so the rotation chain is itself auditable.

Verification examples

import nacl.signing, nacl.encoding, base64, json

# 1. Fetch the signed attestation
import urllib.request
cert = json.loads(urllib.request.urlopen(
    "https://meok.ai/verify?cert=MEOK-EUAIAC-MAIN"
).read())

# 2. Decode the public key
vk = nacl.signing.VerifyKey(
    base64.b64decode(cert["ed25519_public_key"])
)

# 3. Verify
message = cert["canonical_message"].encode("utf-8")
signature = base64.b64decode(cert["signature"])
vk.verify(message, signature)
print("Valid")

curl -sS 'https://meok.ai/verify?cert=MEOK-EUAIAC-MAIN' \
  | jq -r '.signature' | base64 -d > /tmp/sig.bin

# canonical_message and ed25519_public_key are also in the response
# Use any Ed25519 tool. Example with Go:
cat > /tmp/verify.go <<'GO'
package main
import (
  "crypto/ed25519"
  "encoding/base64"
  "fmt"
  "os"
  "io/ioutil"
)
func main() {
  msg, _ := ioutil.ReadFile(os.Args[1])
  sig, _ := base64.StdEncoding.DecodeString(os.Args[2])
  pk, _ := base64.StdEncoding.DecodeString(os.Args[3])
  ok := ed25519.Verify(pk, msg, sig)
  fmt.Println("valid:", ok)
}
GO
go run /tmp/verify.go canonical_message.txt signature_b64 pubkey_b64

import nacl from "tweetnacl";

const cert = await fetch(
  "https://meok.ai/verify?cert=MEOK-EUAIAC-MAIN"
).then(r => r.json());

const message = new TextEncoder().encode(cert.canonical_message);
const signature = base64ToUint8(cert.signature);
const publicKey = base64ToUint8(cert.ed25519_public_key);

const ok = nacl.sign.detached.verify(message, signature, publicKey);
console.log(ok ? "Valid" : "INVALID");
  

Why publish the public key?

Because verification is the only way to make a claim non-circular. If MEOK could revoke, replace, or reinterpret the signing key without notice, the entire attestation system would be a marketing brochure. By publishing the key here, rotation history in public, and verification examples in 3 languages, we make the system adversarial-testable: if our key is compromised, you can prove it. If our attestations are forged, you can disprove it. If our claims are true, you can verify them. See /attestations for the full 5-step verification walkthrough.