Just encrypt the data and pass the key in the url, like so:<p><a href="https:&#x2F;&#x2F;bitf.ly&#x2F;1b4b7ee4fe39312afbfffbe47d831f99#someaeskey" rel="nofollow">https:&#x2F;&#x2F;bitf.ly&#x2F;1b4b7ee4fe39312afbfffbe47d831f99#someaeskey</a><p>That way, the server never sees the key (it&#x27;s client-side and fragments don&#x27;t get sent), but nobody except the recipient can decrypt the data.