It&#x27;s possible under ideal circumstances, but it&#x27;s an uphill battle in the real world. The examples you gave are small potatoes compared to how frequently a master key for criminal cases would be needed and dramatically lower risk. If the NSA leaked their hard drive encryption keys hundreds of people would probably die. Bad yes, but if the master key to (virtually) all encryption schemes in the country is leaked many people would end up getting killed <i>and</i> it would be an economic disaster. Not to mention the potential for limitless privacy abuse, whether in the name of a righteous cause or not.<p>I&#x27;m sure they could work out some sort of subkey scheme and key splitting (via e.g. Shamir&#x27;s scheme) to lower the possibility of compromise and reduce damage if a subkey was leaked, but the possibility won&#x27;t be zero. And with that big of a target the number of people trying to acquire the keys means the chance of the keys eventually being leaked is pretty good.