How to notice when Supplier registration URL Encryption has been tampered

Summary:

On the documentation for this feature we found that when a prospective supplier saves the registration for later completion, the application sends an email to the prospective supplier containing the registration URL. The URL contains an identifier which is encrypted using an encryption key. This prevents users from altering the URL to view registrations submitted by other companies.

If you suspected that registrations have been tampered with, you can regenerate the encryption key.

Content (please ensure you mask any confidential information):

The question is: how to notice that registration URL have been tampered?, and how to notice that there is some user trying to alter the URL to view registrations submitted by other companies?