1 00:00:00,550 --> 00:00:06,720 It is my right choices about your privacy and security you have to have an understanding about encryption. 2 00:00:06,730 --> 00:00:11,520 You don't need to know the hard core mathematics I'll save that for another cause. 3 00:00:11,920 --> 00:00:17,140 I'll give you a crash course now on what is important to know so you can make the right choices about 4 00:00:17,140 --> 00:00:23,530 what cryptosystems to use and understand how encryption can be used to help your security and protect 5 00:00:23,620 --> 00:00:24,770 privacy. 6 00:00:24,820 --> 00:00:31,600 It's not an understatement to say the encryption is absolutely the best tool that we have in our arsenal 7 00:00:31,600 --> 00:00:34,450 to protect others from hackers and trackers. 8 00:00:34,450 --> 00:00:42,970 So what exactly is encryption encryption is a method of transforming readable data called plaintext 9 00:00:43,300 --> 00:00:48,100 into a form that is unreadable which is called ciphertext. 10 00:00:48,100 --> 00:00:56,680 This enables the storage or transmission of data in a form that is only readable and which remains confidential 11 00:00:56,860 --> 00:01:04,440 and private decryption is a method to transform ciphertext back into readable plain text. 12 00:01:04,660 --> 00:01:06,760 And if you do a quick search on Google here 13 00:01:09,640 --> 00:01:17,560 and there you can see the Haseeb CPS which means all the content of the web pages are unreadable to 14 00:01:17,560 --> 00:01:21,780 anyone who can see the day to pass them on the network. 15 00:01:21,790 --> 00:01:28,960 So that means that your Internet service provider or your government maybe they can only see the destination 16 00:01:28,960 --> 00:01:29,590 domain. 17 00:01:29,770 --> 00:01:33,160 So you see this is Google Dakoda UK. 18 00:01:33,310 --> 00:01:39,850 Anybody who's sat between me and Google would only know that I was going to Google they would not know 19 00:01:40,120 --> 00:01:45,730 what I was searching for because this is end to end encryption between my browsers application and the 20 00:01:45,730 --> 00:01:48,020 server to simplify things. 21 00:01:48,040 --> 00:01:50,830 There are two main components of encryption. 22 00:01:50,830 --> 00:01:56,410 You can think about there is the algorithm and there is the key. 23 00:01:56,410 --> 00:02:04,810 So conventionally the algorithm is publicly known and has been scrutinized by many many people in order 24 00:02:04,810 --> 00:02:12,300 to determine if the algorithm is strong and there is the key which is secret and you can think of the 25 00:02:12,300 --> 00:02:15,810 key like a password in that it must be secret. 26 00:02:15,840 --> 00:02:23,820 The algorithm is a bit like a padlock and the key is like a key for that padlock the algorithm and key 27 00:02:23,820 --> 00:02:33,750 combination determines how the plaintext will be jumbled up which is a process of substitution and transposition 28 00:02:34,050 --> 00:02:39,750 of those characters which just means that they move the characters around and they change a character 29 00:02:39,750 --> 00:02:41,510 like a to his ADD. 30 00:02:41,790 --> 00:02:47,670 And if the algorithm or key are weak then the encryption will also be weak. 31 00:02:47,700 --> 00:02:49,250 So let me show you an example. 32 00:02:49,320 --> 00:02:54,870 I want to send the file to a friend Bob but I don't want anyone to read it. 33 00:02:54,870 --> 00:02:58,410 So you need something that can encrypt that file. 34 00:02:58,480 --> 00:03:00,480 I downloaded something that can do that. 35 00:03:00,600 --> 00:03:06,480 And that's when Zipp many people have Wynn's if and I've chosen this deliberately because it's not a 36 00:03:06,480 --> 00:03:11,270 specific tool just for encryption but it enables encryption. 37 00:03:11,280 --> 00:03:23,290 So here we have a file for Bob and if I right click on there when Zip zip file using just an evaluation 38 00:03:23,320 --> 00:03:34,080 version to demo and we can see we have an option here encrypt files if you're not familiar with Zip 39 00:03:34,090 --> 00:03:36,190 is a compression tool. 40 00:03:36,370 --> 00:03:44,920 So it will make the file smaller as I send it packages still into a dot zip file and at the same time 41 00:03:45,760 --> 00:03:49,150 I can choose to encrypt that file. 42 00:03:49,150 --> 00:03:52,420 So if I click on the Encrypt file I look at my options here. 43 00:03:52,600 --> 00:03:57,680 I have the option of 256 bit a s 7:59 Yes. 44 00:03:57,760 --> 00:04:00,240 And legacy Zipp 2.0. 45 00:04:00,350 --> 00:04:08,060 And yes here is a symmetric algorithm which means it uses one key. 46 00:04:08,110 --> 00:04:16,740 So if I click on OK and adds you can give me some warning here then it's going to ask me for the password 47 00:04:17,180 --> 00:04:19,090 and that's going to generate my key. 48 00:04:19,160 --> 00:04:25,700 So yes symmetric encryption algorithm uses just one key. 49 00:04:25,790 --> 00:04:33,660 The password is converted to the key using something called a key creation function. 50 00:04:33,740 --> 00:04:42,580 So that gives is an algorithm of a yes and now a key which is something that is created from our password. 51 00:04:42,590 --> 00:04:51,050 Now you can see one too a bit and you can see 2 5 6 8 2 5 6 is the big lenth or you can consider the 52 00:04:51,050 --> 00:04:52,930 strength of the algorithm. 53 00:04:53,000 --> 00:05:00,830 The higher the number in these algorithms generally the stronger the algorithm but the slower the algorithm 54 00:05:01,100 --> 00:05:02,970 to encrypt and decrypt. 55 00:05:03,020 --> 00:05:09,230 Think about if you had a door and it had many many locks on it it would take you a long time to open 56 00:05:09,230 --> 00:05:14,830 and close the door but it arguably could be more secure because it's got more locks on it. 57 00:05:15,050 --> 00:05:17,860 So again this is the same the higher the bit rate. 58 00:05:18,050 --> 00:05:19,130 The more secure is. 59 00:05:19,130 --> 00:05:28,100 But the long way to encrypt and decrypt the 256 is also the key space which is the number of total possible 60 00:05:28,100 --> 00:05:32,750 different keys that you can have with this encryption algorithm. 61 00:05:32,750 --> 00:05:41,340 Now if you look at this for rotor padlocked in front of you and it has zero 10:9 on each rotor. 62 00:05:41,360 --> 00:05:45,490 Think about how many possible combinations does this have. 63 00:05:47,310 --> 00:05:56,100 Well the answer is ten times ten times ten times ten which is 10000 to go through those manually would 64 00:05:56,250 --> 00:06:03,300 obviously take a long time which is why people could box and they don't try to correct them in this 65 00:06:03,300 --> 00:06:03,980 way. 66 00:06:04,350 --> 00:06:14,310 Yes with two five six bits has one point 1 5 7 9 times 10 to the power of 77 possible keys which is 67 00:06:14,310 --> 00:06:18,230 a number so large there is no word to describe it. 68 00:06:18,240 --> 00:06:19,890 It's a lot. 69 00:06:19,890 --> 00:06:27,300 This means it is very difficult to guess even with very powerful computers doing the guessing what the 70 00:06:27,300 --> 00:06:28,070 key is. 71 00:06:28,140 --> 00:06:35,580 As long as you have used a long and random password to generate a key and people and governments are 72 00:06:35,580 --> 00:06:41,430 trying to create these algorithms all the time we know which are the good ones and we know which are 73 00:06:41,430 --> 00:06:44,990 the bad ones we know which ones are susceptible to being cracked. 74 00:06:44,990 --> 00:06:48,270 And we know which ones are not currently susceptible. 75 00:06:48,270 --> 00:06:54,380 When someone tries to guess what the key is by going through every possible combination. 76 00:06:54,540 --> 00:07:00,530 We call this technique brute forcing or brute force in the key a brute force attack. 77 00:07:00,570 --> 00:07:05,610 You can also do a different type of attack which is called a dictionary attack where you try all the 78 00:07:05,610 --> 00:07:08,420 words in the dictionary against the key. 79 00:07:08,430 --> 00:07:14,430 This is much faster but if the key is in the dictionary the cracking is obviously going to fail and 80 00:07:14,430 --> 00:07:22,290 the last method that is used is a hybrid of the two methods where you take the psychology of human behavior 81 00:07:22,590 --> 00:07:26,300 and combine it with a dictionary and brute force attack. 82 00:07:26,520 --> 00:07:33,600 So an example might be well we know that for example the word monkey is often used in passwords. 83 00:07:33,600 --> 00:07:37,980 It's actually an in the top 10 of words used in passwords. 84 00:07:38,040 --> 00:07:44,390 So we also know that numbers are often added to the end of passwords. 85 00:07:44,520 --> 00:07:52,590 So with that in mind we can use the word monkey from the dictionary and use every sort of number combination 86 00:07:52,610 --> 00:07:56,000 at the end of monkey to see if we can crack the key. 87 00:07:56,110 --> 00:08:01,680 And we're going to talk more on passwords have to set passwords password cracking later on. 88 00:08:01,890 --> 00:08:11,350 So back to wins if and yes here is a symmetric algorithm which means it uses one key. 89 00:08:11,400 --> 00:08:20,040 So if I click on OK and add you give me some warning here and then it's going to ask me for the password 90 00:08:20,480 --> 00:08:22,440 and that's going to generate my key. 91 00:08:22,460 --> 00:08:29,280 So yes symmetric encryption algorithm uses just one key. 92 00:08:29,420 --> 00:08:36,850 Other examples include Des's which is a day of encryption standard trippled there's Blowfish. 93 00:08:37,130 --> 00:08:44,460 Or C for RC 5 or 6 and it still stands for Advanced Encryption Standard. 94 00:08:44,510 --> 00:08:52,430 Now symmetric algorithms are used in most encryption systems you'll be using every day Haiti CPS full 95 00:08:52,430 --> 00:08:57,510 description filing corruption Tor VPN pretty much everything. 96 00:08:57,650 --> 00:09:04,580 And a yes is the common standard for symmetric encryption for maximum protection use where possible 97 00:09:05,140 --> 00:09:14,300 to five six and avoid RC 4 and Dare's if you have the choice yes is fast and currently unbreakable. 98 00:09:14,300 --> 00:09:17,180 So if we enter a strong random password here 99 00:09:20,990 --> 00:09:27,350 and this is telling as we haven't entered want but if we did enter warm then we could send this file 100 00:09:27,590 --> 00:09:34,970 to Bob and we can use any method we chose e-mail for example and even governments militaries people 101 00:09:34,970 --> 00:09:37,850 with lots and lots of resources would find it. 102 00:09:37,970 --> 00:09:47,390 Currently with current computing power impossible to crack encryption and less that password was weak 103 00:09:47,570 --> 00:09:49,430 and will cover in later sections. 104 00:09:49,490 --> 00:09:53,980 What is a strong password what is a weak password depending on the situation.