Encryption, paranoia and virtual machines

[Christopher Browne]

On Fri, Nov 25, 2011 at 1:03 PM, Jamon Camisso
<jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org> wrote:
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> On 11/25/2011 12:35 PM, Christopher Browne wrote:
>> Translucent databases provide better, deeper protection by scrambling
>> the data with encryption algorithms. The solutions use the minimal
>> amount of encryption to ensure that the database is still functional.
>> In the best applications, the personal and sensitive information is
>> protected but the database still delivers the information."
>>
>> The approach that Wayner's book takes is that data that is supposed to
>> be secure is encrypted before it reaches the host, with the
>> consequence that encryption keys never need to be on that host, which
>> is essential to maintain trust when you *don't* trust the system
>> administrator.
>
> That's an interesting approach and makes sense for some use cases.
> However, it presumes that unencrypted data coming from source X never
> hits a disk somewhere. If X doesn't have disk encryption for every
> location where data might be written, then it is a weak point regardless
> of how secure the database is.

No, it assumes that the data is encrypted before transmission.  In
that case, the server never receives it in unencrypted form, so that
risk simply doesn't exist.

> For example, assuming physical access, what is to prevent someone from
> running a forensic recovery tool on say /var/spool files, or on a swap
> partition if either location handled data destined for the encrypted
> database?

What prevents this is that the data was encrypted before it was
received by this server.

> For me at least, while encrypting the whole disk is definitely a
> shot-gun approach, the overhead is slight and reduces complexity. I
> certainly don't notice any performance issues with AES on an SSD.

The problem is that encrypting the whole disk is the "Vitamin C as a
cure for cancer" cure; it is quite likely that it only provides any
protection in peoples' imaginations, rather than providing *actual*
protection.

In order for "whole disk" encryption to function requires that there
be an encryption key on the server, and if that is so, then that key
IS vulnerable to being found by the system administrators.  Not "might
be vulnerable" - it right well *IS* vulnerable to anyone with physical
access, which makes any security being claimed into a mirage.

It doesn't matter how many people think good thoughts about this form
of "security", they may feel good about Sacro Cranial Therapy, or the
merits of homeopathy.  "Good feelings" don't make any of it effectual.
-- 
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question, "How would the Lone Ranger handle this?"
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