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Filesystem encryption is very handy for a notebook computer (I use it, myself), but in a datacenter it's value is a bit more questionable. Where do you store y

Filesystem encryption is very handy for a notebook computer (I use it, myself), but in a datacenter it's value is a bit more questionable. Where do you store your encryption keys? If they're on a removable USB device (for example), you'd have to contact the datacenter personnel to plug them in in the event you had to reboot (which happens from time to time if you perform OS SRU uprades). If the USB device is left in the server and someone gains privileged access to the machine, they've got the key as well as the data. If the USB device is not in the server and someone gains privileged access to the machine, they still have access to the data. The only time disk encryption is valuable is when the machine is off or the disks are being transported.

drewcrawford 14y ago
> The only time disk encryption is valuable is when the machine is off or the disks are being transported. I'm thinking about the case where you have a computer in the home or office environment, e.g. the burglary attack vector. It's not just notebooks that get stolen. I'm also considering the corporate or government espionage vector, where you have a reasonably skilled on-site attacker trying to read or modify the disk contents. In this case you are typing the keys in on boot, and you either ignore the RAM extraction attacks (which are difficult to execute in practice for non-academic attackers) or you can mitigate them by storing in L1 cache and so on. Datacenters have unusually high physical security, and in addition I don't generally store highly sensitive data there (my work doesn't involve PCI compliance etc.) Whereas I do have PCI-level data about myself on my own computers.
- glabifrons 14y ago
  "It's not just notebooks that get stolen." Very good point. I guess I've been working in environments with datacenters too long. :) "I'm also considering the corporate or government espionage vector, where you have a reasonably skilled on-site attacker trying to read or modify the disk contents." Again though, that only protects you if the disks are out or the machine is down. If you have someone with that level of skill within your organization, they'll likely gain access to the running computer where the data has already been made accessible in decrypted form.

drewcrawford 14y ago

> The only time disk encryption is valuable is when the machine is off or the disks are being transported. I'm thinking about the case where you have a computer in the home or office environment, e.g. the burglary attack vector. It's not just notebooks that get stolen. I'm also considering the corporate or government espionage vector, where you have a reasonably skilled on-site attacker trying to read or modify the disk contents. In this case you are typing the keys in on boot, and you either ignore the RAM extraction attacks (which are difficult to execute in practice for non-academic attackers) or you can mitigate them by storing in L1 cache and so on. Datacenters have unusually high physical security, and in addition I don't generally store highly sensitive data there (my work doesn't involve PCI compliance etc.) Whereas I do have PCI-level data about myself on my own computers.

glabifrons 14y ago
"It's not just notebooks that get stolen." Very good point. I guess I've been working in environments with datacenters too long. :) "I'm also considering the corporate or government espionage vector, where you have a reasonably skilled on-site attacker trying to read or modify the disk contents." Again though, that only protects you if the disks are out or the machine is down. If you have someone with that level of skill within your organization, they'll likely gain access to the running computer where the data has already been made accessible in decrypted form.