Double-layered metal mesh walls

As we make our way through layers of security toward the center of the building, our guide describes the unusual walls, which are double layers of metal mesh that run from floor to ceiling. There are no false ceilings here, to prevent intruders from climbing over walls and through the ceilings to gain access.

Down this corridor, through a door protected by a fingerprint scanner, is the data center that issues Symantec's digital certificates to browsers on behalf of businesses, handling 4.5 billion online lookups to verify the validity of the digital signatures using a process called Online Certificate Status Protocol.