My memory on this topic is a bit fuzzy as I was around the accessing of critical data every day, but I didn’t deal directly with getting it. My recollection is you needed two things to get into a federal database. One was the encryption key. The other was something called a “dongle.” The dongle is a piece of hardware that had to be plugged into the computer while you were accessing data. It used a satellite link and referenced an atomic clock. As long as the dongle was present you could interface with the database or other critical system. But without it the encryption key by itself was useless. Now, if he had both and did not have a government job or contract requiring access to that particular part of the database then he was conducing espionage. Even if he never used it, he’d be going to prison...unless he has the Democrat-my-dad’s-vice=president get out of prosecution free card.
I don’t know how old Hunter’s laptop is, but a recent government laptop I saw had an approximately two-inch-wide slot in the side and required a small card (with user’s photo on the one I saw) to be inserted to work.