class ActiveStorage::Blob

to be revealed directly to the user. Always refer to blobs using the signed_id or a verified form of the key.
standard secure-token format from Rails. So it'll look like: XTAPjJCJiuDrLk3TmwyJGpUo. This key is not intended
Returns the key pointing to the file on the service that's associated with this blob. The key is in the

def key
  # We can't wait until the record is first saved to have a key for it
  self[:key] ||= self.class.generate_unique_secure_token
end