Really depends on their comfort/paranoia level. If the device is taken out of their sight for more than a few minutes, they'd be highly suspicious. More so if you are crossing borders of countries known to be hostile.
> Really depends on their comfort/paranoia level. If the device is taken out of their sight for more than a few minutes, they'd be highly suspicious.
If your expected adversary is a nation-state intelligence agency, what do you expect to do? Take your laptop with you everywhere you go, all the time? Leave in your apartment for a theoretical attacker to execute an evil maid attack on it?
FDE is highly useful against ordinary adversaries. People with the financial/staffing/training resources to run surveillance on you 24x7 and access your equipment while it's unattended, that's an entirely other ball game.
You are considering only the extremes. There's also a ground between ordinary adversaries and nation-state agencies.
Take for example China. There are plenty of rumours about business executives taking throw-away electronics while crossing the border or how China installs some random software on people's devices when crossing a border neighbouring a certain province[1]
FDE can also lead to increased suspicion when crossing a border and refusal to unlock the system can pretty much lead to a denial of entry or, worse, detention. FDE also doesn't help in cases when a random border crossing can require installing a malicious boot-loader or a persistent malware somewhere in the system.
In the China story, they might not be installing a persistent bootloader but there's nothing really stopping them from doing that.
Honestly, in certain cases (and I'd rather say, a lot of cases) it's just easier to have no device than deal with what they did to your device after the fact or just sell the device after entering if you are suspicious of it.
A nation-state also has a gap between the most advanced capabilities and what can be used on a routine basis.
For instance a TSA screener is not going to have access to the latest and greatest because information about it gets leaked people will take counter measures.
This isn't about fancy "infosec" threats, this is about TSA breaking or stealing your laptop, or alternatively ordering you to unlock it or they won't let you (a non-American) into the country.
If your expected adversary is a nation-state intelligence agency, what do you expect to do? Take your laptop with you everywhere you go, all the time? Leave in your apartment for a theoretical attacker to execute an evil maid attack on it?
FDE is highly useful against ordinary adversaries. People with the financial/staffing/training resources to run surveillance on you 24x7 and access your equipment while it's unattended, that's an entirely other ball game.