WEBVTT 0 00:01.290 --> 00:02.130 Welcome back! 1 00:02.800 --> 00:10.140 We’ve just seen what a great tool Tor is. It’s used by people all over the world to browse the Web 2 00:10.140 --> 00:17.910 freely, anonymously and circumvent censorship while online surveillance becomes more and more prevalent. 3 00:18.930 --> 00:24.120 It can be used to browse both the surface web and the deep dark web. 4 00:25.500 --> 00:33.030 One of the first questions many users ask is if using Tor or browsing the Dark Web is illegal. 5 00:35.000 --> 00:42.890 The simple answer is that nor using Tor neither browsing the Dark Web is illegal. Tor is just an 6 00:42.890 --> 00:52.190 open network that anonymizes its users and the onion services that run on the dark web are only applications 7 00:52.400 --> 00:55.100 like web, chat or email servers. 8 00:55.640 --> 01:01.070 But most of the activities that occurred on the Dark Web are illegal. 9 01:01.580 --> 01:08.300 Note that there are some countries like China or iran that block the Tor network, by blocking 10 01:08.300 --> 01:12.140 the communication with the Tor relays which are public. 11 01:12.560 --> 01:20.240 So the subject of the legality or illegality of the Dark Web, in those countries of the world, is an ongoing 12 01:20.240 --> 01:20.890 discussion. 13 01:22.070 --> 01:26.720 Keep in mind that there is no such thing as 100 % security. 14 01:27.020 --> 01:31.180 And even Tor has some vulnerabilities. In this lecture 15 01:31.550 --> 01:35.060 I'll show you a few things so you can use it securely. 16 01:36.880 --> 01:43.870 For example by putting the entire Tor circuit together, an adversary could be able to see the IP 17 01:43.870 --> 01:51.700 address of the user on the first relay and the final destination of their web traffic on the last relay, 18 01:52.240 --> 01:56.530 allowing him to match users to their online activity. 19 01:56.860 --> 02:01.080 Some reports showed that the many exit relays are compromised. 20 02:02.380 --> 02:10.090 FBI, Europol and NSA used this attack to shut down hundreds of Dark Web domains and the arrest 21 02:10.220 --> 02:11.700 tens of criminals. 22 02:13.050 --> 02:18.780 If you want to dig deeper into this attack, you should read its analyses done by the Tor project. 23 02:18.990 --> 02:22.310 I’ll also attach it as a resource to this lecture. 24 02:24.210 --> 02:31.650 Let's see what are the best practices when using Tor so that you don't expose yourself to vulnerabilities 25 02:31.950 --> 02:37.320 and exploits that could compromise your identity, privacy or your device. 26 02:38.460 --> 02:46.020 In my opinion, one of the biggest problems with Tor is the traffic isolation, which means sensitive 27 02:46.020 --> 02:49.620 traffic that is transmitted outside to the Tor network. 28 02:50.100 --> 02:57.360 Just imagine that using Tor you download a document that contains the link you'll click on. That link 29 02:57.600 --> 03:02.280 will be opened with your default browser, which is not Tor and your 30 03:02.300 --> 03:11.010 real identity will be exposed. Or a document could embed a script that automatically accesses a server 31 03:11.310 --> 03:12.660 and you are exposed. 32 03:13.650 --> 03:18.330 So you should use Tor in an isolated, security focused system, 33 03:18.510 --> 03:21.690 that runs on a dedicated machine or in a VM. 34 03:22.560 --> 03:27.210 The TAILS Linux, distro we’ve talked about in a previous lecture, 35 03:27.510 --> 03:32.340 is a very good candidate because all traffic goes only though the tor network. 36 03:32.760 --> 03:39.060 There are no other applications that you'll connect normally to the Internet to expose your real IP 37 03:39.060 --> 03:39.540 address. 38 03:41.230 --> 03:48.490 So installing and running the Tor browser on Windows is not the smartest decision if you take 39 03:48.550 --> 03:50.320 anonymity seriously. 40 03:51.570 --> 03:58.380 If you want to check if Tor is working and that your connections are really anonymized, you can visit 41 03:58.500 --> 04:03.630 this website that will tell you if you appear to be coming through the Tor network. 42 04:04.900 --> 04:11.290 In this example, I am not using Tor and the website displays the correct message. 43 04:12.710 --> 04:14.420 Let's try it with Tor! 44 04:15.320 --> 04:20.800 I'm opening the Tor browser and I'll paste this address in the url bar. 45 04:23.060 --> 04:26.110 This is Tor and I'm pasting the address. 46 04:27.740 --> 04:32.990 Congratulations, this browser is configured to use Tor. Perfect. 47 04:34.420 --> 04:37.880 The exit relay is located in Luxembourg. 48 04:38.630 --> 04:44.790 A second rule is that you should not open documents downloaded through the Tor browser while you are 49 04:44.790 --> 04:45.210 online. 50 04:45.630 --> 04:51.390 Open them while you are off line or from an operating system like TAILS. 51 04:51.400 --> 04:56.580 As I've just said, they can contain resources that could reveal your IP address. 52 04:57.660 --> 05:00.270 Similarly, do not use torrents over Tor. 53 05:00.720 --> 05:06.630 They will send out your real IP address in the tracker GET request and deanonymouse you. 54 05:08.330 --> 05:13.700 Do not sign in to websites if you don't want them to find out who you are. 55 05:14.450 --> 05:22.130 Once you sign into a website like Facebook, you have identified yourself to that website and to anyone 56 05:22.130 --> 05:25.550 who might be observing the activity on that site. 57 05:27.190 --> 05:31.930 Use only HTTPS and other protocols that are encrypted. 58 05:32.320 --> 05:34.000 Do not use HTTP. 59 05:35.120 --> 05:39.770 Tor will encrypt the traffic to anonymize you, but the exit relay 60 05:40.010 --> 05:42.200 will have access to the original packet. 61 05:42.560 --> 05:49.040 If it’s not encrypted like say an HTTP packet, then the exit relay can see sensitive data like 62 05:49.070 --> 05:50.960 usernames and passwords. 63 05:51.710 --> 05:58.490 Take a look at this diagram made by the Electronic Frontier Foundation to get a better understanding. 64 06:05.090 --> 06:11.840 Do not visit the Dark Web or visit only sites you trust. The Dark Web is the criminal's heaven. 65 06:12.260 --> 06:15.260 Many sites will try to infect you with malware. 66 06:15.680 --> 06:18.210 Do not click on ads or random links. 67 06:19.940 --> 06:24.960 Changed the security level of the Tor browser to safer or safest. 68 06:27.360 --> 06:28.740 So go to options - 69 06:30.970 --> 06:32.530 Privacy and security - 70 06:34.380 --> 06:41.490 and there you'll find 3 security levels: standard, which is the default, safer and safest. 71 06:42.620 --> 06:50.060 Note that it’s possible that some websites won’t work because components like JS or 72 06:50.060 --> 06:52.070 HTML5 media will be blocked. 73 06:54.350 --> 07:01.450 Use the latest version of the Tor browser because security flaws are often discovered and patched. 74 07:02.520 --> 07:09.630 For example, in June 2019, a critical security flaw that has helped cyber criminals to 75 07:09.630 --> 07:14.760 take full control of systems running vulnerable versions was discovered. 76 07:15.800 --> 07:22.670 Also, note that the Secret Services all over the world monitoring the Tor network for illegal activities. 77 07:23.060 --> 07:25.670 Even if you are just visiting the Dark Web 78 07:25.820 --> 07:28.490 you can become a suspect or even a target. 79 07:29.070 --> 07:29.530 OK. 80 07:29.820 --> 07:30.470 That's all! 81 07:31.350 --> 07:37.740 Follow all of these advice for a secure and anonymous web browsing experience.