1 00:00:00,300 --> 00:00:04,320 So to it's also called robust security. 2 00:00:05,160 --> 00:00:12,630 It is a secure network, which is a type of association used by power stations to establish authentication 3 00:00:12,630 --> 00:00:18,150 or association between them, and it includes the four way handshake. 4 00:00:19,750 --> 00:00:24,760 Now, if you're not familiar with it, we'll briefly discuss the four way handshake, because it's the 5 00:00:24,760 --> 00:00:33,790 process of exchanging four messages between an access point and the client, and that'll generate some 6 00:00:33,790 --> 00:00:40,210 encryption keys, which can be used to encrypt the actual data sent over wireless signals. 7 00:00:41,720 --> 00:00:50,720 The initial authentication process is carried out either by using a pre shared key piece or an extensible 8 00:00:50,720 --> 00:00:53,930 authentication protocol or Hapoel. 9 00:00:54,820 --> 00:01:00,610 That provides an authentication mechanism to devices wishing to attach to a man or a woman. 10 00:01:02,390 --> 00:01:11,630 So after the authentication, a shared secret key is generated called the Pairwise Master Key PMK. 11 00:01:13,470 --> 00:01:22,020 So once the client as the PMK, it and the AP negotiate a new temporary key called the Pairwise Transient 12 00:01:22,020 --> 00:01:23,940 Key, or PAETEC. 13 00:01:25,250 --> 00:01:31,870 So these temporary keys are created dynamically every time the client connects and is changed periodically, 14 00:01:32,590 --> 00:01:39,770 there were a function of the PMK, which is a random number generated by the AP called an instance, 15 00:01:40,430 --> 00:01:47,750 another random number generated by the client that's called an s nonce and the Mac addresses of the 16 00:01:47,750 --> 00:01:49,190 client and the app. 17 00:01:50,230 --> 00:01:57,040 So the reason the keys are created from so many variables basically ensures that they are unique and 18 00:01:57,220 --> 00:01:58,180 non-reporting. 19 00:02:00,510 --> 00:02:07,350 So the four way handshake access point and client are designed to independently prove their acquaintance 20 00:02:07,350 --> 00:02:12,270 with the pesky PMK without disclosing the key. 21 00:02:14,220 --> 00:02:20,940 So instead of disclosing the key, the access point, the AP and the client encrypt messages that can 22 00:02:20,940 --> 00:02:29,160 only be decrypted using PMK and if the messages are decrypted, they will learn about the PMK. 23 00:02:31,860 --> 00:02:37,710 So for way, handshaking is critical for the protection of PMK, for malicious access points. 24 00:02:38,820 --> 00:02:42,380 So the client never has to tell the PMK to the access point. 25 00:02:44,890 --> 00:02:45,910 Within the handshake. 26 00:02:46,860 --> 00:02:54,690 GTK, or the group Temporal Key, is also used to decrypt multicast and broadcast traffic. 27 00:02:56,120 --> 00:03:02,720 So GTK is the key that is shared between all client devices associated with one access point. 28 00:03:03,820 --> 00:03:09,670 So, yeah, for every access point, there will be a different GTK, which will be shared between its 29 00:03:09,670 --> 00:03:10,900 associated devices. 30 00:03:13,060 --> 00:03:22,030 And then finally, the M.S. session is the first key that is generated either from Hapoel or derived 31 00:03:22,030 --> 00:03:24,370 from PDK authentication. 32 00:03:26,020 --> 00:03:32,830 Wow, I know it's a lot, but once we understand the important keys and how they're generated, while 33 00:03:32,830 --> 00:03:36,430 we can then have a look at the actual four way handshake. 34 00:03:37,330 --> 00:03:42,460 With much deeper understanding, all right, so let's work on a visually. 35 00:03:43,850 --> 00:03:51,950 Let's imagine an access point is configured with a tube and the device is trying to connect to it. 36 00:03:53,090 --> 00:03:56,240 So when the user clicks on the access points aside. 37 00:03:57,760 --> 00:04:03,430 So the access point sends an EPA message with an enhanced random number. 38 00:04:04,630 --> 00:04:07,030 To the device to generate the BTK. 39 00:04:08,160 --> 00:04:12,860 The client device knows the Apple Mac address because it's connected to it. 40 00:04:13,950 --> 00:04:18,720 It has PMK assonance and its own Mac address. 41 00:04:20,090 --> 00:04:28,170 So once it receives Arnotts from the access point, it has all the inputs it needs to create the PAETEC. 42 00:04:30,530 --> 00:04:38,450 So once the device is created, it's PAETEC, it sends out essence, which is needed by the access point 43 00:04:38,960 --> 00:04:47,810 to generate the PDK as well as MISI, which is message integrity check to make sure that the access 44 00:04:47,810 --> 00:04:52,190 point can verify whether the message is corrupted or modified. 45 00:04:53,930 --> 00:05:01,370 All right, so once assonance is received by the AP, it, too, can generate PDK for unicast traffic 46 00:05:01,370 --> 00:05:01,970 encryption. 47 00:05:03,520 --> 00:05:08,200 So then the AP verifies message two by checking Amishi. 48 00:05:09,330 --> 00:05:14,970 And Eveillard It constructs and sends the GTK with another MEAC. 49 00:05:16,280 --> 00:05:25,330 The EPA verifies message three by checking that Mesi and if it's valid, yesterday sends a confirmation 50 00:05:25,330 --> 00:05:26,290 to the AP. 51 00:05:27,840 --> 00:05:31,590 All right, so once the four way handshake is completed successfully. 52 00:05:32,750 --> 00:05:39,290 Now, all unicast traffic will be encrypted with PAETEC and all multicast traffic will be encrypted 53 00:05:39,290 --> 00:05:44,330 via GTK, which was created in the four way handshake process.