The state representing the number of attempts must be stored somewhere, and thus a determined adversary could eventually corrupt it.<p>Look, there&#x27;s a big difference between trusting known ciphers that have been well studied by the world&#x27;s top cryptographers, and a proprietary TPM chip that relies on security-through-obscurity.<p>The history of embedding secrets into black boxes is a history of them being broken. This isn&#x27;t a theoretical concern, it&#x27;s a very practical one.