1 00:00:02,900 --> 00:00:07,840 This far we've talked about data confidentiality. 2 00:00:07,900 --> 00:00:09,500 This is the most relevant aspect. 3 00:00:09,520 --> 00:00:15,470 And the first thing that springs to mind when data protection is concerned. 4 00:00:15,670 --> 00:00:17,960 But this doesn't always have to be the case. 5 00:00:20,510 --> 00:00:23,600 Sometimes the integrity of data is equally important. 6 00:00:27,080 --> 00:00:33,290 Data integrity refers to a situation when a given message has not been modified by an unauthorized person. 7 00:00:38,600 --> 00:00:46,290 Data integrity can be maintained by adding specific checksums to the data this method also helps protecting 8 00:00:46,290 --> 00:00:48,670 the integrity of operating system files. 9 00:00:51,180 --> 00:00:56,790 If a document you open has a different check sum than that of a document saved by a trusted user. 10 00:00:56,790 --> 00:01:01,730 This points to data integrity corruption. 11 00:01:01,890 --> 00:01:03,900 Why is integrity so important. 12 00:01:05,920 --> 00:01:08,250 Let's use online orders as an example. 13 00:01:09,680 --> 00:01:12,160 If someone has spired that we've ordered five books. 14 00:01:12,200 --> 00:01:20,290 This usually doesn't bother us but if that person modifies the order value from 5 to 500 books we would 15 00:01:20,290 --> 00:01:26,090 be less than happy integrity is a vital feature of information. 16 00:01:35,500 --> 00:01:38,920 Data authenticity is another key aspect to data security 17 00:01:41,630 --> 00:01:44,840 authenticity is a bit broader in scope than integrity. 18 00:01:48,690 --> 00:01:53,950 Authenticity is a feature of information that ensures that the sender of the data stream is legitimate. 19 00:01:55,190 --> 00:01:58,670 And that the data has not been modified after it was sent by a trusted sender 20 00:02:01,680 --> 00:02:08,750 This feature can be verified through the use of digital signatures will cover this incoming module's 21 00:02:11,390 --> 00:02:12,790 as we stressed before. 22 00:02:12,800 --> 00:02:15,180 You should not put too much faith in technology. 23 00:02:17,940 --> 00:02:21,330 You can see an example of why limited trust is the best option. 24 00:02:22,770 --> 00:02:31,300 It's a certificate for signing crucial information contained in system files or X Files. 25 00:02:31,440 --> 00:02:38,760 It was stolen and used to sign malicious software authenticity is verified through digital signatures 26 00:02:38,760 --> 00:02:41,460 on files that are usually generated from certificates 27 00:02:44,020 --> 00:02:46,270 certificate has an assigned level of trust. 28 00:02:46,290 --> 00:02:47,340 A user can give 29 00:02:53,280 --> 00:02:55,870 the less feature of information is its availability 30 00:03:00,250 --> 00:03:09,640 data availability is specified in an SLA service level agreement I.T. departments and business customers 31 00:03:09,640 --> 00:03:15,570 are bound with the terms and conditions of an SLA. 32 00:03:15,780 --> 00:03:21,780 The specifications of this contract define the maximum tolerable length of service unavailability and 33 00:03:21,780 --> 00:03:25,410 determine the amounts of information that can be lost after a disaster. 34 00:03:27,720 --> 00:03:30,780 You can find lots of information on soldiers on the Internet. 35 00:03:35,150 --> 00:03:43,770 The key elements of the agreement are recovery time objective or T-O which is the duration of time in 36 00:03:43,770 --> 00:03:45,720 which a service can be unavailable. 37 00:03:47,300 --> 00:03:52,540 Most often calculated in a percentage the closer to 100 percent. 38 00:03:52,660 --> 00:04:02,220 The longer the information needs to be available recovery point objective RPO which is the amount of 39 00:04:02,220 --> 00:04:04,700 data that can be lost in the event of a failure. 40 00:04:07,280 --> 00:04:13,510 The recovery time objective forms the foundation of all s.l AES. 41 00:04:13,740 --> 00:04:22,680 The measures the non-negotiable duration of time within which information or services can be unavailable. 42 00:04:22,700 --> 00:04:32,040 It is usually expressed as a number of Neyens if a given service is to be provided 365 days a year 24 43 00:04:32,040 --> 00:04:35,630 hours a day seven days a week. 44 00:04:35,640 --> 00:04:43,020 This means that an RTL value that has five nines ninety nine point nine nine nine percent can only be 45 00:04:43,020 --> 00:04:47,440 shut down for whatever reason maintenance attacks threats. 46 00:04:48,000 --> 00:04:49,470 For five minutes in a year 47 00:04:53,300 --> 00:04:58,160 agreeing on a five nines article means that a given service or information has to be protected in a 48 00:04:58,160 --> 00:04:59,210 special way. 49 00:05:02,180 --> 00:05:06,560 It's impossible to provide an RTL this high if data is stored in one system only 50 00:05:09,940 --> 00:05:13,200 hosting companies usually agreed to a four digit are. 51 00:05:16,260 --> 00:05:24,550 Under the same assumptions 3:09 mean that a service can shut down for 8 hours per year maximum. 52 00:05:24,660 --> 00:05:28,690 You can't expect your only computer to be set up for the whole year without interruption. 53 00:05:31,210 --> 00:05:36,820 And 8 hours will probably be too little to successfully deal with an attack or to restore a system after 54 00:05:36,820 --> 00:05:37,960 a failure. 55 00:05:39,730 --> 00:05:44,700 Another part of an SLA which is defined in all contracts of this type is a recovery point objective 56 00:05:46,280 --> 00:05:51,640 which is the measure that determines the amount of data that can be lost after an attack. 57 00:05:51,650 --> 00:05:56,700 It's easier to ensure a recovery point objective of 0 percent. 58 00:05:56,720 --> 00:06:02,520 It's a matter of replicating data and creating backups then to ensure and RTU equaling ninety nine point 59 00:06:02,540 --> 00:06:07,090 ninety nine percent in the case of the RTU. 60 00:06:07,130 --> 00:06:10,580 I have saleability comes with the need for investing in expensive equipment 61 00:06:13,780 --> 00:06:18,490 ASL is are becoming increasingly popular and it's quite possible that you'll often be asked to sign 62 00:06:18,490 --> 00:06:21,730 an SLA that determines the RPO as a 0 percent 63 00:06:24,150 --> 00:06:29,270 businesses need to guarantee that whatever happens no data will be lost from the system. 64 00:06:31,690 --> 00:06:38,440 We have few technologies that can ensure implementing good values of RTU and RPO will mention them later 65 00:06:38,440 --> 00:06:40,490 on in the next modules of this course. 66 00:06:43,910 --> 00:06:49,910 High availability of services usually require the use of specialist technologies. 67 00:06:50,000 --> 00:06:52,740 There will also be covered in the next part of this course. 68 00:07:00,290 --> 00:07:00,770 Thank you.