Decryption Performance

From: Aaron (anonymous_at_discussions.microsoft.com)
Date: 04/23/04 

Date: Fri, 23 Apr 2004 09:21:03 -0700

We are currently looking into ways to protect our data in a SQL Server database from being viewed by users and/or administrators on the client PC. One option is to encrypt the fields that we feel are important enough to protect. In our case, that includes at least half the fields on our main information table.

As a test, we encrypted fields in a sample database using a SH1 hash algorithm. A test app reads the table and decrypts the encrypted fields. The initial tests show the process of reading the table and decrypting the encrypted fields runs 3 times slower than without decryption (which is understandable). I am looking for either decryption algorithms or possible other strategies to use so the decryption process is faster. This database is read-only, so the speed of the reads is important.

If anyone knows of some good websites out there that would have examples of what I am looking for, that would help a lot.

Thanks in advance.