PCFBMode pcfb = PCFBMode.create(cipher, iv);
System.arraycopy(iv, 0, data, 0, iv.length);
pcfb.blockEncipher(hash, 0, hash.length);
System.arraycopy(hash, 0, data, iv.length, hash.length);
if(logMINOR) Logger.minor(this, "Payload length: "+length+" padded length "+data.length);
data[hash.length+iv.length] = (byte) pcfb.encipher((byte)(length>>8));
data[hash.length+iv.length+1] = (byte) pcfb.encipher((byte)length);
pcfb.blockEncipher(output, 0, output.length);
System.arraycopy(output, 0, data, hash.length+iv.length+2, output.length);
Util.randomBytes(node.fastWeakRandom, data, hash.length+iv.length+2+output.length, paddingLength);