Posted by Erland Sommarskog on 12/04/06 22:56

Volker Hetzer (firstname.lastname@ieee.org) writes:
> ttt.tas@gmail.com schrieb:
>> actually, i'll be using MSSQL for my DB.
>> the problem is as follow, i want to develop some small exe file that
>> will read the fields of unencrypted DB and encrypt it field by field.
>> actually i'll get this DB from a client and he doesn't want me to view
>> the DB content, its already an exisiting one, so i should develop him
>> some exe file that he will run on this DB and will encrypt all its
>> fields, and not the DB as a whole, so i can then take this DB and work
>> on the encrypted fields instead.

Actually, we had this sort of a problem with one of our customers, and
we developed a very cheesy low-budget solution. To our defense, I should
add that it was the customer's own idea.

In our case, the problem is that the customer cannot let us into the
database for support cases, if their customer data is visible, due the
regulations on financial secrecy in the country where they are active.

What they do when they need us to access the database, is that they
pull a handle (that is, they run a small application), that copies
all sensitive customer information to a database we do not have access
to, and then they replace this data with a string of question marks.
Once they are done, they copy the real data back.

That could serve as inspiration for ttt.tas's problem. Rather than
encrypting the entire database, just overwrite the sensitive information
with nonsense, and save the real database locally at the client.
Provided that there is a need to merge back at all. If there is no
need to merge back, then you can be more frivolous with destroying
the current information.

Note that depending on the purpose of getting a local copy, the
operation may be more or less successful. If the purpose is to
examine performance problems, replacing a lot of data can change
presumption, resulting in problems in reproducing performance
issues.
--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx

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