Here is a concrete implementation : SecureString in .NET http://msdn.microsoft.com/en-us/library/system.security.securestring.aspx http://msdn.microsoft.com/e

Here is a concrete implementation : SecureString in .NET http://msdn.microsoft.com/en-us/library/system.security.securestring.aspx http://msdn.microsoft.com/en-us/library/system.security.secu... It's using DAPI which derives the encryption key from the user password.