Goals of Protection
Principles of Protection
Domain of Protection
Access Matrix
Implementation of Access Matrix
Access Control
Revocation of Access Rights
Capability-Based Systems
Language-Based Protection
Goals of Protection
Principles of Protection
Domain of Protection
Access Matrix
Implementation of Access Matrix
Access Control
Revocation of Access Rights
Capability-Based Systems
Language-Based Protection
This presentation covers the understanding of system calls for various resource management and covers system calls for file management in details. The understanding of using system calls helps to start with working with device driver programming on Unix/Linux OS.
Deadlocks-An Unconditional Waiting Situation in Operating System. We must make sure of This concept well before understanding deep in to Operating System. This PPT will understands you to get how the deadlocks Occur and how can we Detect, avoid and Prevent the deadlocks in Operating Systems.
This presentation covers the understanding of system calls for various resource management and covers system calls for file management in details. The understanding of using system calls helps to start with working with device driver programming on Unix/Linux OS.
Deadlocks-An Unconditional Waiting Situation in Operating System. We must make sure of This concept well before understanding deep in to Operating System. This PPT will understands you to get how the deadlocks Occur and how can we Detect, avoid and Prevent the deadlocks in Operating Systems.
proposed solution to resource sharing and security against unauthorize.docxtodd921
proposed solution to resource sharing and security against unauthorized resource access that you view as the ideal balance between sharing, protection, and complexity of implementing users and groups in an operating system of your choice. Provide an instance that comes close to your ideal balance between resource sharing and protection against unauthorized resource access.
Describe any security issues or benefits that you envision with the proposed solution.
Describe any file access issues that may exist with the proposed solution.
Solution
Shared resources, also known as network resources, refer to computer data, information, or hardware devices that can be easily accessed from a remote computer through a local area network (LAN) or enterprise intranet. Successful shared resource access allows users to operate as if the shared resource were on their own computer. The most frequently used shared network environment objects are files, data, multimedia and hardware resources like printers, fax machines and scanners.
Operating systems have to balance the conflicting goals of convenient resource sharing and protection against unauthorized resource access. Windows offers a variety of mechanisms such as user and group permissions, shares, and access control lists with inheritance. On the other hand, Linux has a much simpler implementation of users and groups.
Following methods are adopted to achieve resoure security: 1) using global user identifiers to replace traditional user identifiers; 2) implanting global user identifiers into kernel entities such as processes and files; 3) adopting an access control mechanism based on global user identifiers. The most important feature of our approach is that we implement it by introducing innovative elements into operating system kernels. Compared with middleware approaches, our method can provide better security, performance and compatibility.
A file management system is a type of software that manages data files in a computer system. It has limited capabilities and is designed to manage individual or group files, such as special office documents and records. It may display report details, like owner, creation date, state of completion and similar features useful in an office environment.
A file management system is also known as a file manager.
Problems addressed by modern file systems:
Issues to consider:
Contiguous allocation (also called \"extent-based\"): allocate files like segmented memory (contiguous run of sectors). Keep a free list of unused areas of the disk. When creating a file, make the user specify its length, allocate all the space at once. Descriptor contains location and size. Example: IBM OS/360.
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It is an overview about the Linux operating system and more beneficial to the students of BSCIT and BSCCS and other computerr related courses. It will provide you all the main points of about Linux in short and sweet language.
The primary focus of the PPT is to develop the initial skill of using HTML & CSS programming language to develop a static web page like Portfolio.
This PowerPoint Presentation is of Front End Design.
This PPT will give an entire view on developing the static web page.
This PPT covers the entire topic of Macro Assembler. This Includes the topic such as design of a macro assembler, 3 passes of macro assembler etc.
This is the PPT of System Programming.
This is an PPT about the Icons that are used in Graphical User Interface, the Images that are used for developing a web page & the use of multimedia for various purpose.
This is an PowerPoint Presentation of Front End Design.
This PPT describes about the "Project Tracking" activity & statistical process control at Infosys.
It covers the entire topic such as project tracking, activities tracking, defect tracking, issue tracking, etc.
It covers all main activity of SPC such as SPC analysis, control chart for SPC etc.
This PowerPoint presentation is of "Software Project Management".
This is the PowerPoint presentation on the topic "Peephole Optimization". This presentation covers the entire topic of peephole optimization.
This PowerPoint presentation is of Compiler Design.
This is the PPT of "Routing in Manet". It covers the entire topic of routing protocol.
This PowerPoint presentation is of Data Communication & Computer Network.
Secant method in Numerical & Statistical MethodMeghaj Mallick
This is an PPT of a Mathematical Paper i.e Numerical & Statistical Method. It contsin the following topic such as "Secant method in Numerical & Statistical Method ".
This presentation by Morris Kleiner (University of Minnesota), was made during the discussion “Competition and Regulation in Professions and Occupations” held at the Working Party No. 2 on Competition and Regulation on 10 June 2024. More papers and presentations on the topic can be found out at oe.cd/crps.
This presentation was uploaded with the author’s consent.
0x01 - Newton's Third Law: Static vs. Dynamic AbusersOWASP Beja
f you offer a service on the web, odds are that someone will abuse it. Be it an API, a SaaS, a PaaS, or even a static website, someone somewhere will try to figure out a way to use it to their own needs. In this talk we'll compare measures that are effective against static attackers and how to battle a dynamic attacker who adapts to your counter-measures.
About the Speaker
===============
Diogo Sousa, Engineering Manager @ Canonical
An opinionated individual with an interest in cryptography and its intersection with secure software development.
This presentation, created by Syed Faiz ul Hassan, explores the profound influence of media on public perception and behavior. It delves into the evolution of media from oral traditions to modern digital and social media platforms. Key topics include the role of media in information propagation, socialization, crisis awareness, globalization, and education. The presentation also examines media influence through agenda setting, propaganda, and manipulative techniques used by advertisers and marketers. Furthermore, it highlights the impact of surveillance enabled by media technologies on personal behavior and preferences. Through this comprehensive overview, the presentation aims to shed light on how media shapes collective consciousness and public opinion.
Acorn Recovery: Restore IT infra within minutesIP ServerOne
Introducing Acorn Recovery as a Service, a simple, fast, and secure managed disaster recovery (DRaaS) by IP ServerOne. A DR solution that helps restore your IT infra within minutes.
2. It is implemented to prevent interferences with the
use of files both logical and physical address space.
It can be of two types :-
(I)Protection
(II)Security
Any file system may have two types of threats
i.e. INTERNAL and EXTERNAL
3. Let there be multiple users (U)in the system
using different resources (R)of system i.e.
U1
U2
U3
U4
U5
R1
R2
If U3 wants to access R1 then this threats
is internal and leads to protection
If any external users want to access R1 or
R2 then this threats leads to security.
INTERNAL
4. PROTECTION :-
It deals with threats information that are internal.
It provides mechanism for controlling the access to
program process user to a resource.
SECURITY :-
It deals with threats that are external.
It includes firewall and encryption technique.
5. ••
•
• Protection refers to a mechanism for controlling the access
of programs, processes, or users to the resources defined
by a computer system.
Protection ensures that the resources of the computer are
used in a proper way.
It ensure that each object accessed correctly and only by
those processes that are allowed to do so.
OS designer faces challenge of creating a protection scheme
that cannot be by passed by any software that may be
created in the future
6. • Safe sharing of common logical address
space or common physical address space.
• Fair and reliable resources usage.
• Detect malfunction before they
contaminate the system.
7. • Access control is concerned with determining the allowed
activities of valid users, mediating every attempt by a user to
access a resource in the system.
Basic Terminology are :
Object: An entity that contains or receives information.
•
access to the- Access to an object potentially implies
information it contains.
example. File, programs, printer, disk, etc.
performAccess rights: The permisiion granted to a user
to an operation
example. read, write, execute etc
9. •
•
•
•
• Domain = collection of objects and a set of access rights for
each of the objects
A process operates within a Protection Domain that specifies
the resources that the process may access.
Each domain defines a set of objects and the types of
operations that may be invoked on each object.
The ability to execute an operation on an object is an access
right
System will consists of such multiple domains each having
certain predefined access right on different object
10. • During execution of the process it can change the domain
this is called domain switching
•
•
•
A domain can be realized in a variety of ways:
Each user may be a domain. In this case, the set of objects
that can be accessed depends on the identity of the user.
Each process may be a domain. In this case, the set of
objects that can be accessed depends on the identity of the
process.
11. Example of Unix:
In the UNIX operating system, a domain is associated with
the user.
In Unix operating system user ID’s use for identify the
domain.
12. Allocate space to the file so that disk space is utilized in a efficient
manner.
FACTOR TO CONSIDER FOR FILE ALLOCATION
1) Processing speed: If we are allocating file where
sequential and random access is very slow then allocation is
inefficient.
2) Ability to use multisector and multitract transfer
3) Disk space utilization: File should be stored or allocated such
that maximum number of file can be stored in the disk.
4) Main memory requirement : It should be less.
13. 1.Each file occupies a set if contiguous addresses on disk.
2.Linear ordering.
3.Location of a file is defined by the disk address of the first
block and its length.
4.Both sequential and direct /random access are supported.
Disadvantages:-
--Finding space for new file.
--leads to external fragmentations.
14. First fit : Allocate at first space that is capable of storing file.
Best fit : Allocate the smallest space that is big enough to store the
file.
Worst fit : Allocate the largest space.
15. 1. Solves all the problems of contiguous
allocation . Each file is a linked list of disk
blocks.
2. No External fragmentation.
3. Can be used only for sequential access of file.
16. 1.Solves the problem of linked allocation.
2. In this all the pointers are brought together into
one location called index blocks.
3.Each file has its own index block.