Re: Decryption Performance

From: Alek Davis (alek_xDOTx_davis_xATx_intel_xDOTx_com)
Date: 04/24/04

  • Next message: Chris Rolon: "Re: Decryption Performance" 
    Date: Fri, 23 Apr 2004 17:42:04 -0700

    Aaron,

    There is something wrong with your statement: you cannot decrypt data
    "encrypted" with SHA-1 algorithm (I assume that you misspelled SH1). SHA-1
    is a hashing (not encryption) algorithm and you cannot decrypt hashed data.
    If you are able to decrypt data, then you must be using some sort of
    encryption, not hashing. Depending on the encryption algorithm you are using
    (DES, 3DES, Rijndael, etc) and encryption parameters and implementation
    (block size, managed/unmanaged, etc), there is a chance you may be able to
    improve performance, but I would not expect a miracle. Check this report
    (Performance Comparison: Security Design Choices):
    http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnbda/html/bdadotnetarch15.asp;
    it may give you some ideas. I assume that you decrypt data in C#/VB.NET
    code. If this is correct, the best bet would be to find the fastest (and
    reasonably secure) algorithm and implementation. I also assume that your
    application is optimized (for example, you do not create a new
    encryptor/decryptor for every record). Another alternative would be to use
    third party tools, which encrypt data directly in the database, but I
    haven't used them and do not know what their performance/security/ease of
    use are.

    Alek

    "Aaron" <anonymous@discussions.microsoft.com> wrote in message
    news:AD0AF639-C6A1-46C3-8BC8-AB83930C6A95@microsoft.com...
    >
    > 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.

  • Next message: Chris Rolon: "Re: Decryption Performance"

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