Update README.md

README.md

@@ -21,10 +21,12 @@ The first version of the protocol is a representation of binary data. Each laser
 | HANDSHAKE_SIGNAL_DURATION | 100 | The duration of handshake signal in milliseconds. The handshake is one long signal sending before upcoming data transmission. Should be longer than one bit duration. It should be the same on both transmitter and receiver ends. |
 | BIT_DURATION | - | The duration of one bit in milliseconds and depends on the exact hardware. It should be the same on both transmitter and receiver ends. The ordinary digital photoresistor module can handle downt to 70ms per bit|
 
+### DTLP 2
+The same DTLP 1 but with encryption and decryption of data. The encryption should be sync and use one key for encrypting and decrypting. The Encryption algorithm is depending on the exact situation and solution and will not be defined here.
+By encryption and decryption of data, in case of [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) the potential 3rd party transmitter of an attacker will not be able to send a wrong data, because the receiver will try to decrypt the incoming payload and it'll not be able to process the data since there will be an error of decrypting the data. So the encryption of the data solves two potential issues: be sure the transmitter is known transmitter; be sure that the data is not processed by MITM attack.
 
-# Upcoming Versions
-- The upcoming 2nd version of the protcol will include speed optimization and an ability to encrypt the data before transmission and decrypt after receiving. By encryption and decryption of data, in case of [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) the potential 3rd party transmitter of an attacker will not be able to send a wrong data, because the receiver will try to decrypt the incoming payload and it'll not be able to process the data since there will be an error of decrypting the data. So the encryption of the data solves to potential issues: be sure the transmitter is known transmitter; be sure that the data is not processed by MITM attack.
 
+# Upcoming Versions
 - The upcoming 3rd version will involve 8 transmitters and 8 receivers. Each laser and receiver will represent a bit. By that way in one bit period (BIT_DURATION) the transmitter will be able to send a whole byte and the receiver will be able to receive it. x8 for speed.
 
 - The upcoming 4th version will include the following: 8 lasers for 1 and 8 lasers for 0 bits for the transmitter; 8 photodiodes for 1 and 8 photodiodes for 0 bits for the receiver. That's it 16 lasers for a transmitter and 16 photodiodes for receiver. By that way there will be implemented PDT([parallel data transmission](https://en.wikipedia.org/wiki/Parallel_communication)). x2 for speed.