asp.net - Encrypt query string -

iam trying send employeeid in page using query string want send in encrypted format.

if knows answer, great help.

from http://www.infoexpediters.com/securequerystring.cs:

public string encrypt(string serializedquerystring)     {         byte[] buffer = encoding.ascii.getbytes(serializedquerystring);         tripledescryptoserviceprovider des = new tripledescryptoserviceprovider();         md5cryptoserviceprovider md5 = new md5cryptoserviceprovider();         des.key = md5.computehash(asciiencoding.ascii.getbytes(cryptokey));         des.iv = iv;         return convert.tobase64string(             des.createencryptor().transformfinalblock(                 buffer,                 0,                 buffer.length             )         );     }      public string decrypt(string encryptedquerystring)     {         try         {             byte[] buffer = convert.frombase64string(encryptedquerystring);             tripledescryptoserviceprovider des = new tripledescryptoserviceprovider();             md5cryptoserviceprovider md5 = new md5cryptoserviceprovider();             des.key = md5.computehash(asciiencoding.ascii.getbytes(cryptokey));             des.iv = iv;             return encoding.ascii.getstring(                 des.createdecryptor().transformfinalblock(                     buffer,                     0,                     buffer.length                 )             );         }         catch (cryptographicexception)         {             throw new invalidquerystringexception();         }         catch (formatexception)         {             throw new invalidquerystringexception();         }     }