Draft proposal of how crypto will be implemented added. TODO updated.

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+Draft proposal for how crypto will be implemented.
+
+
+Encryption library used: http://nacl.cr.yp.to/
+
+
+When running the program for the first time the crypto_box_keypair() function is used to 
+generate the users public-private key pair. (32 bytes each)
+
+The generated public key is set as the client_id of the peer.
+
+Adding a friend:
+    Alice adds bob to her friends list by adding his 32 byte public key (client_id) to his friends list.
+    2 cases:
+        case 1: Alice adds Bobs public key and bob waits for Alice to attempt to connect to him.
+        case 2: Bob and Alice add their respective public keys to their friends list at the same time.
+    
+    case 1:
+        Alice connects to Bob and sends a data packet (friends request) like so:
+            [char with a value of 01][Alice's Public key (client_id) (32 bits)][Random nonce (24 bits)][Encrypted message]
+
+        Where the encrypted message is encrypted with crypto_box() (using Bobs public key, Alice's private key 
+        and the nonce (randomly generated 24bits)) and is a message from Alice in which she tells Bob who she is.
+        Ex: hello bob it's me alice -_- add me pl0x.
+        
+        Bob receives the request and decrypts the message using the function crypto_box_open()
+        
+        If the message decrypts successfully: 
+            If Alice is already in Bobs friends list: case 2
+            If Alice is not in Bob's friends list: Bob is prompt to add Alice and is shown the message from her.
+        If Bobs accepts Alice's friends request he adds her public key to his friends list.
+
+    case 2:
+        Bob and Alice both have the others public key in their friends list, they are ready for the next step: Connecting to an already added friend
+        
+
+In the next step.
+only crypto_box() is used for encryption and only crypto_box_open() for decryption (just like in the last step.)
+
+
+Connecting to an already added friend:
+    Alice and Bob are friends.
+    As soon as they connect they each send themselves the following packet (encrypted part encrypted with the public nonce in the packet
+    the public key of the receiver and private key of the sender)
+        [char with a value of 02][Random nonce (24 bits)][Encrypted message containing a random 24 bit base nonce]
+    If the packet is decrypted successfully:
+    Each start using the secret nonce provided by the other to encrypt data packets (adding to it + 1 for each packet.)
+    Data packet:
+        [char with a value of 03][Encrypted data]
+    Each data packet received it is decrypted using the secret nonce sent to the other(with +1 added for the first packet +2 for the second, etc...)
+    Every data packet sent is encrypted using the secret nonce we received (with +1 added for the first packet +2 for the second, etc...)
+    The encrypted connection is only deemed successful when a data packet is received and decrypted successfully.