File Protection

File protection and the three techniques used in file protection :
1. file naming
2.passwords
3.access control

1. File Protection 4/9/2018

2. outline 4/9/2018

3. File protection 4/9/2018 The Protection of a file is mostly needed in multi-user environment where a file is shared among several users. On system which does not permit access to the files of other users, protection is not required. Protection mechanism must provide controlled access by restricting the types of files which can be made. Access is permitted or denied depending upon several factors, one of which is the type of access requested.

4. 4/9/2018 Several different types of operations may be controlled. These operations are: Reading from the file. Writing on the file. Executing the file by loading into main memory. Writing new information at the end of a file. Deleting the file and releasing the space.

5. 4/9/2018 FILE NAMING PASSWORDS ACCESS CONTROL

6. File naming 4/9/2018

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9. How to name your files? Nobody likes unorganized folders. If everyone took the initiative to name their files correctly, there wouldn't be such a hassle downloading and sorting files. This is an example of poor mp3 naming. 4/9/2018

10. 4/9/2018 You must be much more descriptive. Give all the information that is necessary. Do not use ID tags. ID tags hide the truth, and hiding the truth is wrong. - Instead of ID tags, use parenthesis and underscores to specify meta data.

11. 4/9/2018 Name your files and folders wisely..! You must adhere to file-naming conventions when saving files : 1. Case sensitivity – upper and lower case are different True in Linux and Unix variations, not in Windows 2. Maximum length (Windows 260 characters) 3. Spaces allowed 4. Digits allowed 5. \ / : * ? " < > | not allowed (Special Characters) 6. File names not allowed (con, nul, prn ) File extensions provide clues to the file contents. OS uses extensions to know which application created the file and the internal format of the file.

12. Filename extensions 4/9/2018 Extension Type of Document Application .doc or .docx Word processing document Microsoft Word .xls or .xlsx Workbook Microsoft Excel .ppt or .pptx PowerPoint presentation MS PowerPoint . accdb Database Microsoft Access .gif, .jpg, . png Images Windows Image Viewer .mp4, .mp3 Videos, audio Windows Media .zip Compressed file WinZip .pdf Portable Document Format Adobe Acrobat .htm or .html Web page Hypertext Markup Language

13. passwords 4/9/2018

14. 4/9/2018 In this approach, password is associated with each file. Just as a password is required to access a computer system, access to each file will be also controlled by a password. A password is a string of characters used to verify the identity of a user during the  authentication   process. Passwords are typically used in conjuncture with a username; they are designed to be known only to the user and allow that user to gain access to a device, application or website. 

15. Limitations There are, however, several disadvantages to this scheme: If we associate a separate password with each file, the number of passwords that need to he remembered are quite large, making the scheme impractical. If only one password is used for all the files, then once it is discovered all files are accessible. Some systems allow a user to associate a password with a subdirectory rather than an individual file, to deal with this problem. 4/9/2018

16. Commonly, only one password is associated with each file. Thus protection is on an all-or-nothing basis. To provide protection on a more detailed level, multiple Passwords are needed. 4/9/2018 HACKERS!!

17. ACCESS CONTROL 4/9/2018

18. 4/9/2018 ACCESS CONTROL |SECURITY TECHNIQUE | RESTRICT USERS

19. 4/9/2018 ACCESS LISTS APPROACH : to make access dependent on the identity of the user. Multiple users >> different types of access to a file or directory. ‘‘ An access list can be associated with each file and directory, specifying the user name and the types of access allowed- for each user. ’’ WORKING!!! USER REQUESTS ACCESS OS CHECKS THE ACCESS LIST IF (USER IS PRESENT IN AL) ACCESS ALLOWED; ELSE ACCESS DENIED; //protection violation

20. Disadvantages of access lists 4/9/2018 This has two undesirable consequences: Constructing such a list may be a tedious and unrewarding task , especially if we not know in advance the list of users in the system. The directory entry which previously was of fixed size needs now to be of variable size, resulting in space management being more complicated. These problems can be resolved by using a condensed version of the access list.( ACCESS GROUPS)

21. ACCESS GROUPS To condense the length of the access list , many systems recognize three classifications of users in connection with each file: Owner The user who created the file. Universe(Others) All other users in the system Group A set of users who are sharing the file and need similar access.

22. A situation to illustrate the working of access groups : 4/9/2018 Consider a person, X, who is working on a new project. She has hired three graduate students (A, B, C) to work on the project. X C B A Owner Group

23. Re protection associated with this file is as follows: X should be able to invoke all operations on the file. A, B and C should only be able to read, write, and execute the file. They should be allowed to delete the file. 4/9/2018

24. All other users should be able to execute the file. (X is interested in letting as many people as possible play the game in order to obtain appropriate feedback.) To achieve such a protection, a new group must be created with member A, B, C. The name of the group must be then associated with the file project, and the access-right must be set in accordance with the policy that is outlined . 4/9/2018 Others(universe)

25. 4/9/2018 Rockstar North (OWNER) FURTHERMORE… Programmer(s) Obbe Vermeij Adam Fowler Artist(s) Aaron Garbut Writer(s) Dan Houser James Worrall Composer(s) Lex Horton (GROUP)

26. Universe(users) 4/9/2018 EXECUTE

27. 4/9/2018 Secure Social Profiles..

28. 4/9/2018 Secure Confidential Data..

29. Thank you!! Compiled by- Kriti Katyayan (16070124024) Ameya Kshirsagar (16070124025) Vedang Lad(16070124026) 4/9/2018 Keep your files safe!