Why bring encryption into the glass house? To paraphrase bank
robber Willie Sutton, “because that’s where the data
is.”
To date, most data center security efforts have been focused on
protecting against Internet threats.
However, IT can no longer ignore physical security: Thieves
recently broke into the Chicago data center of managed Web hosting
provider C I Host and stole server hardware—for the fourth
time. Meanwhile, backup tapes are frequent targets for theft
because they’re often out of IT’s direct possession.
The Privacy Rights Clearinghouse Web site documents more than 40
cases of tape theft since 2005, and it’s likely that far more
were never reported. In the InformationWeek 2008 Strategic Security
Survey, the theft of computers or storage systems was among the top
five breaches seen as most likely to occur in 2009.
Clearly, encrypting hard drives and tapes is
vital to protect data. So why aren’t organizations rushing to
sign on? The complexity of managing keys is a top deterrent to
ubiquitous encryption. After all, there are many ways to encrypt,
but key management is where all these projects succeed or fail. And
failure is most likely to occur several years out, after the hole
has been dug quite deep. Some information must be kept for decades,
after all, and storing the keys needed to access that data securely
for 10 or 20 years is a challenge.
Fortunately, advances in managing keys as well as new options
for encrypting data at each step within the backup process make it
much less likely lost keys will come back to haunt you. Most of the
vendors we spoke with understand the problem and are working to
solve it. RSA’s Key Management Suite, for example, works with
encryption products from RSA partners to give IT a single
management point for all encryption keys. Encryption vendors also
have started to build key management into their products or offer
these capabilities as options for companies with modest
requirements.
Tales of the Tapes
Security analysts love the idea of encrypting all data on the host
before it’s even sent to a backup server. This guarantees
end-to-end privacy and minimizes the number of places where
mistakes can be made. And plenty of products provide this
capability. Symantec’s NetBackup is a good example—just
generate a key and click a box within the user interface to enable
encryption of any data set. The backup server instructs the client
to encrypt on the fly.
This approach has downsides, however. By encrypting data at the
host, deduplication has to happen at the server. And encryption
adds load to the server, lengthening the backup window and perhaps
affecting performance. Moreover, encrypted data is supposed to be
indistinguishable from random data, so it tends to render
tape-drive compression completely ineffective. Since most tape
drives claim a hardware compression rate of at least 2-to-1,
server-side encryption can easily double your tape consumption.
But key management may well be the worst problem. Backup vendors
are only now starting to add key management capabilities to their
software; most still rely on the backup admin to handle management
tasks. You’d think someone would take this off our hands.
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