"Most people aware of high-security needs employ several laptops for segregating the various persons they talk to, and the classification levels of the information they handle," Dave Aitel, CEO of cyber security consultancy Immunity Inc., told BI. "Snowden was used to this from working at the government, and probably used this technique by only handling the documents on one laptop and communicating with the others. That way at no time would his documents ever be directly reachable by someone who hacked one of his communications laptops."
Cyber expert and CEO of TrustedSec David Kennedy detailed how a security system with four laptops and encrypted thumb drives would work in practice.
"You keep separate laptops in order to compartmentalize the data and ensure that only certain data is only on one system vs. the other in order to keep certain types of data that jointly together could be very damaging of taken," said Kennedy, a white hat hacker who breaks into systems for major companies. "Additionally, it may require a certain sequence of laptops and multiple encryption keys in order to disable them."