Running "node lib-dqx-test.mjs" will:
1. Generate a secret key and print it out.
2. Generate a public key and print it out.
3. Generate a second key pair and print out only the public key.
4. Hash the second public key with SHA-256.
5. Sign the hash with the secret key of the first key pair.
6. Verify the signature with the public key of the first key pair.
