computer security

COMPUTER SECURITY

Computer security is the protection of the items you value, called the assets of a computer or computer system. There are many types of assets, involving hardware, software, data, people, processes, or combinations of these. To determine what to protect, we must first identify what has value and to whom.

  A computer device (including hardware, added components, and accessories) is certainly an asset. Because most computer hardware is pretty useless without programs, the software is also an asset. Software includes the operating system, utilities and device handlers; applications such as word processing, media players or email handlers; and even programs that you may have written yourself. Much hardware and software is offthe-shelf, meaning that it is commercially available (not custom-made for your purpose) and that you can easily get a replacement. The thing that makes your computer unique and important to you is its content: photos, tunes, papers, email messages, projects, calendar information, books (with your annotations), contact information, code you created, and the like. Thus, data items on a computer are assets, too. Unlike most hardware and software, data can be hard—if not impossible—to recreate or replace. These assets are all shown in Figure 1-2.

  These three things—hardware, software, and data—contain or express things like the design for your next new product, the photos from your recent vacation, the chapters of your new book, or the genome sequence resulting from your recent research. All of these things represent intellectual endeavor or property, and they have value that differs from one person or organization to another. It is that value that makes them assets worthy of protection, and they are the elements we want to protect. Other assets—such as access to data, quality of service, processes, human users, and network connectivity—deserve protection, too; they are affected or enabled by the hardware, software, and data. So in most cases, protecting hardware, software, and data covers these other assets as well.

   In this information, unless we specifically distinguish between hardware, software, and data, we refer to all these assets as the computer system, or sometimes as the computer. And because processors are embedded in so many devices, we also need to think about such variations as mobile phones, implanted pacemakers, heating controllers, and automobiles. Even if the primary purpose of the device is not computing, the device’s embedded computer can be involved in security incidents and represents an asset worthy of protection.

FIGURE 1-2 Computer Objects of Value

Hardware:
• Computer
• Devices (disk drives, memory, printer)
• Network gear
Software:
• Operating system
• Utilities (antivirus)
• Commercial applications (word processing, photo editing)
• Individual applications
Data:
• Documents
• Photos
• Music, videos
• Email
• Class projects

What is a Firewall?

Firewall

A firewall is software used to maintain the security of a private network. Firewalls block unauthorized access to or from private networks and are often employed to prevent unauthorized Web users or illicit software from gaining access to private networks connected to the Internet. A firewall may be implemented using hardware, software, or a combination of both.

(Firewall between Client & Server)

                 

A firewall is recognized as the first line of defense in securing sensitive information. For better safety, the data can be encrypted.

Firewalls generally use two or more of the following methods:

• Packet Filtering: Firewalls filter packets that attempt to enter or leave a network and either accept or reject them depending on the predefined set of filter rules.
• Application Gateway: The application gateway technique employs security methods applied to certain applications such as Telnet and File Transfer Protocol servers.
• Circuit-Level Gateway: A circuit-level gateway applies these methods when a connection such as Transmission Control Protocol is established and packets start to move.
• Proxy Servers: Proxy servers can mask real network addresses and intercept every message that enters or leaves a network.
• Stateful Inspection or Dynamic Packet Filtering: This method compares not just the header information, but also a packet’s most important inbound and outbound data parts. These are then compared to a trusted information database for characteristic matches. This determines whether the information is authorized to cross the firewall into the network.

What is C ?

C Language:

C is a computer programming language. That means that you can use C to create lists of instructions for a computer to follow. C is one of thousands of programming languages currently in use. C has been around for several decades and has won widespread acceptance because it gives programmers maximum control and efficiency. C is an easy language to learn. It is a bit more cryptic in its style than some other languages, but you get beyond that fairly quickly.

C is what is called a compiled language. This means that once you write your C program, you must run it through a C compiler to turn your program into an executable that the computer can run (execute). The C program is the human-readable form, while the executable that comes out of the compiler is the machine-readable and executable form. What this means is that to write and run a C program, you must have access to a C compiler. If you are using a UNIX machine (for example, if you are writing CGI scripts in C on your host's UNIX computer, or if you are a student working on a lab's UNIX machine), the C compiler is available for free. It is called either "cc" or "gcc" and is available on the command line. If you are a student, then the school will likely provide you with a compiler -- find out what the school is using and learn about it. If you are working at home on a Windows machine, you are going to need to download a free C compiler or purchase a commercial compiler. A widely used commercial compiler is Microsoft's Visual C++ environment (it compiles both C and C++ programs). Unfortunately, this program costs several hundred dollars. If you do not have hundreds of dollars to spend on a commercial compiler, then you can use one of the free compilers available on the Web. See http://delorie.com/djgpp/ as a starting point in your search.

C++: Program to calculate age in years, months and days.

Input the date of birth of a person and find his age in terms of year, month and days. using class.

Age Calculator of a Person

Code:

//for more program please visit www.programtubenotes.blogspot.in 

#include<iostream>
#include<conio.h>
#include<stdlib.h>
#define WELCOME "WELCOME TO AGE CALCULATOR"

using namespace std;


class Age
{
    private:
        int day,month,year;
    public:
        void getdata();   //input date
        friend void show(Age t, Age b, Age a);//calculate age
};
void Age::getdata()
{
    cin>>day>>month>>year;
}
void show(Age t, Age b, Age a)
{
    if(t.day<b.day)
    {
        t.month--;
        t.day+=30;
    }
    a.day=t.day-b.day;
    if(t.month<b.month)
    {
        t.year--;
        t.month+=12;
    }
    a.month=t.month-b.month;
    a.year=t.year-b.year;
    cout<<"\nYour Age is  "<<a.year<<" year "<<a.month<<" month "<<a.day<<" day ";
   
    cout<<"\n\n\nCreated By:- Mr. Maheswar Sahoo\nFor more application please contact:-maheswarsahoo47@gmail.com";
    cout<<"\nThank You...\n\n\n";
}
int main()
{
    system("COLOR 4C");  //for background color
    Age birth;
    Age today,age;
    cout<<"\t\t\t\t"<<WELCOME;
    cout<<"\n\n\nEnter date of today (dd mm yyyy) : ";
    today.getdata();
    system("COLOR 1C");   //change background color
    cout<<"\nEnter date of birth (dd mm yyyy) : ";
    birth.getdata();
    show(today,birth,age);
    return 0;
}

We suggest this video to watch:

Download Output .exe File https://drive.google.com/open?id=0B4CL13xQ1tkTZWhQTmVCMFpKZ3

Related word:

Class

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