1 00:00:00,360 --> 00:00:08,280 In 1990, the U.S. Office of Naval Research set out to develop a method for anonymously navigating the 2 00:00:08,280 --> 00:00:10,330 Internet for spying purposes. 3 00:00:10,920 --> 00:00:18,150 So the plan was to set up a network of routers that was separate from the Internet routers that could 4 00:00:18,150 --> 00:00:25,080 encrypt the traffic and that only stored the unencrypted IP address of previous router, meaning all 5 00:00:25,080 --> 00:00:28,810 of the router address along the way were encrypted. 6 00:00:30,060 --> 00:00:35,940 So the idea was that anyone watching the traffic could not determine the origin or destination of the 7 00:00:35,940 --> 00:00:36,390 data. 8 00:00:36,810 --> 00:00:40,590 This research became known as the onion router. 9 00:00:40,620 --> 00:00:47,490 Or we can see the tower project in nine in 2002, not 19 in 2002. 10 00:00:48,000 --> 00:00:54,790 So it's now available to anyone to use for relatively safe and anonymous navigation to the web. 11 00:00:55,560 --> 00:00:58,030 So, guys, let's see how it all works. 12 00:00:58,560 --> 00:01:03,390 So we're having this whole, as you can see, that map, how it works. 13 00:01:05,190 --> 00:01:12,030 OK, shoegaze, as you can see that as we all know, that packets send our daughter are not sent over 14 00:01:12,030 --> 00:01:19,590 the regular router so closely monitored by so many, but rather are sent over a network of over 7000 15 00:01:19,590 --> 00:01:21,270 routers around the world. 16 00:01:21,930 --> 00:01:26,240 So thanks to the volunteers who allows their computers to be used by Tom. 17 00:01:27,420 --> 00:01:34,920 So on top of using totally separate Troughton network thobe and the data so opposed, like we having 18 00:01:34,920 --> 00:01:40,980 this example in which, as you can see, that this computer is of Jeff and here we are having Mike. 19 00:01:41,520 --> 00:01:48,630 OK, so guys, when Jeff wants to talk to Mike, they he has to send a message, but he doesn't want 20 00:01:48,810 --> 00:01:51,790 message to be tracked. 21 00:01:52,620 --> 00:01:55,920 So what they used to do, he used Don Network. 22 00:01:55,920 --> 00:01:57,870 So of will do so. 23 00:01:57,900 --> 00:01:58,920 Let's understand that. 24 00:01:59,220 --> 00:02:06,810 So when he sends the max the packet data packet so that packet will contain IP address of destination 25 00:02:06,960 --> 00:02:10,270 and IP address of the sender in the encrypted form. 26 00:02:10,290 --> 00:02:14,820 So when you send the message then as you can see that this is a symbol of encryption. 27 00:02:15,030 --> 00:02:16,510 So it sends the message. 28 00:02:16,800 --> 00:02:17,550 So this will. 29 00:02:18,970 --> 00:02:27,010 Supposed like this will rotate to the node, which is the door node, so if you want to talk to his 30 00:02:27,010 --> 00:02:31,840 friend in normal maintenance of what he can do here is he can send a message like this. 31 00:02:33,540 --> 00:02:39,480 Like this, like this and like this, so this is the way in normal Internet, he can send a message, 32 00:02:39,490 --> 00:02:42,510 but if he's using Tor saw, what he can do here is. 33 00:02:44,880 --> 00:02:50,760 He says the data packet and the packet contains the IP address of destination and IP address of sender 34 00:02:50,910 --> 00:02:56,110 and a packet software, including that data packet, it will go to the door. 35 00:02:56,370 --> 00:02:58,480 So this is called door note. 36 00:02:59,070 --> 00:03:06,540 So when the data packet reaches here, it seemed this particular node will include the data packet sorted, 37 00:03:06,650 --> 00:03:12,120 decrypted it a packet, and after decrypting the data packet, what it will do, it will again in the 38 00:03:12,120 --> 00:03:17,030 data packet with its IP address and the destination interest. 39 00:03:17,430 --> 00:03:19,470 So it will send the data packet. 40 00:03:19,650 --> 00:03:25,930 It will be again encrypted and received by the end of the door, not after that. 41 00:03:25,950 --> 00:03:30,680 This process will going on and the message will be sent to the mike. 42 00:03:31,110 --> 00:03:38,730 So what if someone track someone traced this particular suppose that if someone sitting in between these 43 00:03:38,730 --> 00:03:43,680 two computers can help track this, intercept this particular data packets, what he can see, he can 44 00:03:43,680 --> 00:03:50,040 only see the previous IP address of sending missing previous means, this particular machine. 45 00:03:50,280 --> 00:03:53,040 But data packet is send it by this particular machine. 46 00:03:53,050 --> 00:03:56,270 So this this is how this is how he's safe. 47 00:03:57,000 --> 00:03:57,590 He's safe. 48 00:03:57,870 --> 00:04:03,120 So he only knows the IP address of this particular machine, but the data was send it by this particular 49 00:04:03,120 --> 00:04:03,410 machine. 50 00:04:03,420 --> 00:04:05,340 So that is why how tall is useful. 51 00:04:05,340 --> 00:04:06,930 That is how that is useful. 52 00:04:07,590 --> 00:04:09,120 So this is the way it works. 53 00:04:09,710 --> 00:04:17,310 OK, it simply created a packet inside this destination and the sender doesn't in that particular data 54 00:04:17,310 --> 00:04:20,520 packet is encrypted and it will send to the door. 55 00:04:20,520 --> 00:04:21,910 No, to this door. 56 00:04:21,940 --> 00:04:25,560 And so as we all know, that there are 7000 outas. 57 00:04:25,920 --> 00:04:32,640 So this will send to a download and after's getting the data packet download will decrypted it a packet 58 00:04:32,640 --> 00:04:42,620 and it will simply give the Stenders IP address and the IP address and again in Deko encrypted and again 59 00:04:42,650 --> 00:04:48,630 send it to the next node, which as you can see here and when here, same process will goes on and then 60 00:04:49,140 --> 00:04:50,170 I will receive the message. 61 00:04:50,460 --> 00:04:53,290 So this is how Tor works and this is how you can work with it. 62 00:04:53,550 --> 00:04:58,050 So guys, this is all for this lecture from the next lecture on which we are going to see how to install 63 00:04:58,710 --> 00:05:00,760 browser and how we can take use of this. 64 00:05:00,810 --> 00:05:01,260 Thank you.