Explain the concept of 'Public Key Cryptography' and 'Digital Signatures' using a detailed metaphor involving a royal court and physical wax seals. Do not use technical terms like 'algorithm', 'hash', 'key', or 'encryption'. Instead, map these technical terms to elements of your royal court metaphor (e.g., the King's private ring, the public herald, etc.). Ensure the explanation accurately reflects how non-repudiation works in the digital world.