&gt; If the key is cracked, then the attackers can create a brand new file, and make it look like its existence had been certified in 2005.<p>What? If someone cryptographically timestamped a particular signed file in 2005, even if Eve cracks the original public key and can now produce arbitrary new signed files with that key, they still do not have <i>2005</i> timestamps for any of those new files! They could only make 2015 timestamps. That&#x27;s the whole point of cryptographic timestamps.