How to encrypt databse file

hey dude thanx for ur reply..it worked for me
i just encrypted imp fields of db rather dan db file
thanks once again
cheers!!!

Hi Kassim,

You are right. In the code the "output" variable should be used in here

FileStream outputStream = new FileStream(output,FileMode.OpenOrCreate,FileAccess.Write);

"output" is the path to save the encrypted file.

The key is exaclty that, a key that both party (encryptor and decryptor) should know. For example

// Encrypt

"Plain text" -> encrypt using key="my key" -> encrypted text = "lkjljlkjlkjlkjl"

// Decrypt

"lkjljlkjlkjlkjl" -> decrypt using key="my key" -> "Plain text"

if the key is other than "my key" then we would not be able to get the result back. The longer the key the more difficult to hack due to more possible combinations.

Please, in decrypt method you should also change the use of output variable. Usually the key is a string converted to a byte array. This both method are usefull to encrypt and decrypt files. You should consider what you really want, if fields of databases encrypted or if you want the db files encrypted itself. If you want to encrypt for example a field that stores passwords then you may consider a Hash Algorithm rather than encrypt the whole db file.

Hope this helps.

thanx for your code, it help me to sum extend..but i dint understood sum part of the

in encrypt method u dint used output and key variable, which is a parameter
and what is the role of key in this encryption, and waht value i should to use as a key

so whenevr i want to load db in appliction i hav to call Decrypt method evrytime???

hi friend,
Here is some basic code for encrypting data by using a symmetric key in SQL Server 2005.

OPEN SYMMETRIC KEY PrivateData DECRYPTION  BY PASSWORD ='Password'
 
 CREATE TABLE UserData
 (Data VARBINARY(255))
 
 DECLARE @Key_GUID UNIQUEIDENTIFIER
 
 SELECT @Key_GUID = Key_GUID
 FROM sys.symmetric_keys
 WHERE Name = 'PrivateData'
 INSERT INTO UserData
 (Data)
 VALUES
 (EncryptByKey(@Key_Guid, 'RawData', 1))
 
 SELECT Data
 FROM UserData
 
 SELECT CONVERT(VARCHAR(20), DecryptByKey(UserData.Data, 1)) AS Data
 FROM UserData
 
 DROP TABLE UserData
 
 CLOSE SYMMETRIC KEY PrivateData

Enjoy Coding.....

===========================================
Don't Forget to mark it as answer :)

Does How to: Encrypt a Column of Data help?

Hi,

Since you need to encrypt and decrypt the file representing your DB you may use a symmetric encryption algorithm. The .NET framework provides classes representing such algorithms see System.Security.Cryptography namespace. Basically you will have an input (will by the byte[] representing your file), a key (requiered to decrypt in a latter time) and the byte[] output than can be stored in as a file.

check this sample code. It should solve your problem.


// ENCRYPT

public void EncryptFile(string input, string output, byte[] key)
        {
            FileStream inputStream = new FileStream(input,FileMode.Open,FileAccess.Read);
            FileStream outputStream = new FileStream(input,FileMode.OpenOrCreate,FileAccess.Write);

            SymmetricAlgorithm alg = new RijndaelManaged();
            alg.Key = key;

            // READ THE DB FILE
            byte[] data = new byte[inputStream.Length];
            inputStream.Read(data,0,(int)data.Length);

            ICryptoTransform encryptor = alg.CreateEncryptor();
            CryptoStream stream = new CryptoStream(outputStream,encryptor,CryptoStreamMode.Write);

            // WRITE THE DATA ENCRYPTING
            stream.Write(data,0,data.Length);

            // CLOSE SEGMENT
            stream.Close();
            inputStream.Close();
            outputStream.Close();
        }


// DECRYPT

        public void DecryptFile(string input, string output, byte[] key)
        {
            FileStream inputStream = new FileStream(input,FileMode.Open,FileAccess.Read);
            FileStream outputStream = new FileStream(input,FileMode.OpenOrCreate,FileAccess.Write);

            SymmetricAlgorithm alg = new RijndaelManaged();
            alg.Key = key;

            // READ THE ECRYPTED FILE
            byte[] data = new byte[inputStream.Length];
            inputStream.Read(data,0,(int)data.Length);

            ICryptoTransform decryptor = alg.CreateDecryptor();
            CryptoStream stream = new CryptoStream(inputStream,decryptor,CryptoStreamMode.Read);

            // WRITE THE DATA ENCRYPTING
            stream.Read(data,0,data.Length);

            // CLOSE SEGMENT
            stream.Close();
            inputStream.Close();
            outputStream.Close();
        }



If this solve your problem please mark this question as answered by this reply. Keep coding and we keep learning. Thanks