Answer

How to set 16 0's key value on TripleDESCryptoServiceProvider.

Gaurav Sharma

13y

6.7k

I want to set a known value for key in 3DES algorithm. But i have observed after using TripleDesCryptoServiceProvider in C# code and assigning all 16 0's as key my program gave error "Cryptographic Exception was unhandled"
     Please have a look on my piece of code,

   byte[] IV=new byte[8] {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
   byte[] key = new byte[24] { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};

            TripleDESCryptoServiceProvider tDESalg = new TripleDESCryptoServiceProvider();

            // Create a string to encrypt.
            byte[] testData = new byte[8] { 0xD6,0x52,0xF9,0xCF,0x3F,0x31,0x7D,0xEC};


            tDESalg.IV = IV;
            tDESalg.Padding = PaddingMode.None;

            tDESalg.Key = key;    // Error Cryptographic Exception was unhandled. Specified key is a known weak key for 'TripleDES' and can't be used.

         How to solve this issue. I don't want to use default key value coming from TDES and as per my requirement key value must all zero.