// decrypting e[] with key k[] into a[]
// e[] = array to be decrypted
// k[] = key of truly random gibberish
// a[] = original data
byte[] a = new byte[e.length];
for ( int i=0; i<e.length; i++ )
   {
   a[i] = (byte)( e[i] ^ k[i] );
   }