Security

1. A calendar subscription link is input
2. Using a secret key stored in Cloudflare's Secrets Store, the original URL is encrypted. A new, private URL of format .../?url=encrypted_url is generated. The original URL is not stored
3. When a calendar application requests event information from the private URL, the private URL is decrypted, after which event details are fetched, modified to show only as 'Busy', and passed on to the calendar application.

Key security features:

• the original URL is not stored by Cloudflare
• event details are not stored by Cloudflare
• the original URL exists within the private URL in encrypted form

Please let me know if you have any security upgrade suggestions!