byte[] k2 = new byte[7];
System.arraycopy(sessionKey, 0, k1, 0, 7);
System.arraycopy(sessionKey, 7, k2, 0, 7);
DES k3 = new DES(k1);
DES k4 = new DES(k2);
byte[] output1 = new byte[8];
byte[] output2 = new byte[8];
k3.encrypt(input, output1);
k4.encrypt(output1, output2);
return output2;
}