[dba-SQLServer] Fwd: Security & encryption

Francisco Tapia fhtapia at gmail.com
Thu May 12 11:14:42 CDT 2005


I found some additional information on encrypting tables and data for that 
matter, One article suggested to follow suit in the Label security that 
Oracle has laid out...

http://www.oracle.com/technology//index.html

Additionally this thread had some useful hints.. (duplicating relevant post)
 *Armstrong <http://www.sqlservercentral.com/forums/userinfo.aspx?id=30902>* 
  *RE: Encryption with XP Crypt*
Posted 2/11/2004 9:52:00 AM 
<http://www.sqlservercentral.com/forums/post.aspx?forumid=6&messageid=99857&edit=1>
**
  
We are using xp_crypt to encrypt certain fields in our database. If you use 
this product and you want to "encrypt a particular table", you would do that 
by encrypting each field in the table separately. Because encryption and 
decryption take cpu time, I would suggest you encrypt only what is 
necessary.

xp_crypt provides you with a .dll that provides you with some extended 
stored proceudres you can call from T-SQL. The parts of the product that I 
have used work as advertised. Technical support is by e-mail but is quite 
prompt.

One of the issues that you will want to address early on is where to store 
your encryption keys. As you know, there are two basic types of encryption: 
*private key *and *public key*. 

Private key encryption uses the same key to both encrypt and decrypt. This 
makes it imperative that the key be kept secret, because anybody who has a 
copy of the key will be able to read your data. Because neither people nor 
computers are all that good at keeping secrets, some organizations even go 
so far as to place their private keys in hardware devices. The hardware 
device is designed to never reveal the key; rather you give it a string of 
data and the device does the encryption/decryption internally. This approach 
can provide very good security. One company which sells this kind of device 
is Rainbow Technologies (www.rainbow.com <http://www.rainbow.com/>). The 
devices work well but the implementation effort can be steep! (xp_crypt is 
MUCH simpler to use)

Public key encryption uses a published key for encryption (the public key), 
and a different key for decryption (the private key). Public key encryption 
works well, is computationally intensive, and its encrypted data tends to 
take up a lot of space. We use it because it fits what we do: lots of people 
here need to encrypt data (order entry with credit card information), but 
only a few people need to decrypt (sending credit card info to the clearing 
house for payment). In other words, many people use a public key, but only a 
few use a private key so the key management is bearable.

To sum up, we are using xp_crypt in a software-only solution because it was 
straightforward, not expensive, and was much better than storing sensitive 
information in the clear. However, hardware devices do provide better key 
management which helps security. Which one you choose would depend on your 
requirements and your budget.
 
And of course more links re: rainbow
http://www.safenet-inc.com/solutions/ent/HiSpeedEnc.asp?WT.MC_id=sol-hse00018

It also occured to me that there really are situations where data should 
remain encrypted such as banking info etc. Those databases SHOULD really be 
encrypted so that if they were hacked, the critical information would still 
remain safe.

On 5/11/05, Charlotte Foust <cfoust at infostatsystems.com> wrote:
> 
> Certainly, but that ability to render the data meaningless or deny
> access ALWAYS exists in the dba, regardless of whether the data is
> encrypted. If you can't trust a dba or you won't trust one to protect
> your interests and your data, then you should be keeping your data
> someplace other than in a database.
> 
> Charlotte Foust
> 
> 
> -----Original Message-----
> From: nicholas van [mailto:nick at frasiervan.com]
> Sent: Wednesday, May 11, 2005 11:00 AM
> To: dba-sqlserver at databaseadvisors.com
> Subject: RE: [dba-SQLServer] Fwd: Security & encryption
> 
> Mark has covered most of the main design points.
> 
> As always, Higher Security = Greater Inconvenience
> 
> I think it may be interesting to clarify what is meant by not letting
> the sysadmins and DBA get into the data. Even if the data itself is
> encrypted the DBA and System adminstrators will have the enough access
> to seriously compromise the integrity of the data. Even if you cannot
> know the exact data because it is encrypted, we are talking about people
> who can effectively deny access to all others, or in other ways render
> the data meaningless.
> 
> As was pointed out with the encyption scheme, the most important point
> of control is to make sure that the people who have access to the
> encrypted data do not also have access to the encryption keys. Where we
> are right now we deal with some confidential data and we make sure the
> people with the devryption key access do not have database access, and
> vice versa.
> 
> ---------- Original Message ----------------------------------
> From: "Charlotte Foust" <cfoust at infostatsystems.com>
> Reply-To: dba-sqlserver at databaseadvisors.com
> Date: Wed, 11 May 2005 10:14:55 -0700
> 
> >Somehow, I think you're going to have to work out a compromise with
> >them. Could you promise not to peek, wear a blindfold when the table
> >is open, point out that they get a dba with the database, not one from
> >column A OR one from column B? <g>
> >
> >Charlotte Foust
> >
> >
> >-----Original Message-----
> >From: Roz Clarke [mailto:roz.clarke at donnslaw.co.uk]
> >Sent: Wednesday, May 11, 2005 8:31 AM
> >To: 'dba-sqlserver at databaseadvisors.com'
> >Subject: RE: [dba-SQLServer] Fwd: Security & encryption
> >
> >
> >I AM a DBA I can trust!!! But HR sadly don't feel the same way. :(
> >
> 
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-- 
-Francisco
http://pcthis.blogspot.com |PC news with out the jargon!
http://sqlthis.blogspot.com | Tsql and More...



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