Encryption and Key Management solution

[peemousse]

Hello,

background

I'm currently in charge of the PCI compliance for my company. I have some question related to requirement 3 and the encryption/key management part.
I've read a lot in various forums devoted to PCI compliance, but I'm having a hard time figuring out how to implement a compliant solution.

To give you the background:

- we have a website where customers enter their personal information (PAN, Name etc...)
- those data are stored on a MSSQL database.

The data stored in the MSSQL database are encrypted using column encryption (using AES).

This solution is obviously not compliant because the encryption key is generated on the server and the key management is non-existent.

question

Basically, what is the most simple, straightforward, and common way to encrypt PAN data on MSSQL in a way that is PCI compliant ?

work in progress

Use StrongKey (there is an excellent topic here: http://www.strongauth.com/forum/index.php?topic=44.0).
It might take time to implement and it might need some modification on our web application, so development time as well...
We might need to buys HSM for the servers who don't have a TPM integrated.

Use an Appliance (to generate, store, distribute the keys...)
It seems to be the easiest way if we don't have budget issue, which we don't have...
Any recommendation on a good products for key management?
What would be the cost of such applicance?

It seems to be best solution for the long term...

I don't think MSSQL 2005 have the ability to have the cryptographic key hierarchy to be managed by an external source such as Hardware Security Module (HSM)... so I guess the encryption will have to be done on the webapplication... and then stored in the DB... is that correct?

Home made solution
I was thinking of the following scenario:
- two random strings are generated on openssl for example using a livecd.
- the two strings are XOR to produce a symmetric key (DEK, dual control and split knowledge?)
- use this key as a symetric key for the database (i'm not sure how it exactly work... I'm a bit confused with the database master key?).
- use asymetric encryption to encrypt the two random strings(KEK1 and KEK2) used to produce the DEK.
- put KEK1 and KEK2 on usbkey, for example and lock them in the company safe in two different boxes (how to manage to private Keys?)

Then change the symmetric key used annualy like recommended.

Does this last scenario make sense?

The Symmetric Key will be entered manually at some point in the database... i'm not a DBA and my knowledge is limited on MSSQL administration, is there any recommendation to achieve this the right way?

Like you see I'm quite confused and would appreciate some insight and recommendation.

Thanks for your help.

ps: yes we need to store the card holder data :)

[jbhall56]

On the appliance side of your question. The most common appliance we run across is the nCipher keyAuthority (http://www.ncipher.com/en/Products/Key%20Management/keyAuthority.aspx). Two other appliances that we have clients using include Alliance Key Manager from Patrick Townsend (http://www.patownsend.com/productDetails.php?prodId=68) and NetApp's Lifetime Key Management (http://www.netapp.com/us/products/storage-security-systems/lifetime-key/). These all support key management principles that are PCI compliant. I definitely prefer the appliance approach over "roll your own" if an organization can afford it. It just takes all of the maintenance and enhancement off of your plate so that you can focus on 'real' issues.

[peemousse]

Thanks for your answer jbhall56 :)

I have couple more questions if you don't mind...

What is the most common process to encrypt data on a database with an appliance distributing the Keys... I still have a hard time to figure out. MSSQL 2005 doesn't accept key via an external source so I guess most of the data needs to be encrypted before hand. Is that correct?

1/customer fill in the form with credit card number
2/Webserver makes a request to the appliance for a Key (if so how does it work in general? is it via some cryptographic library? does it need a lot of development on the web application...?)
3/the key is used the encrypt the data
4/the data are saved encrypted on the database...

Sorry for the silly question, I just want to be sure i understand correctly.

thanks for your help :)

[lyalc]

While that model can work, it may require your develoerps to maintain more 'security' code than business logic. Also, it means the key os traversing the network, even if SSL protected.
Many sites simply have the app send the data to en/decrypted to the appliance across the network, then use the resulting output as per business logic. This may be simpler to develop and support.

lyalc

[peemousse]

Thanks for your answers lyalc :)