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.

What does Honeypot mean?

A honeypot is a decoy computer system for trapping hackers or tracking unconventional or new hacking methods. Honeypots are designed to purposely engage and deceive hackers and identify malicious activities performed over the Internet.

Multiple honeypots can be set on a network to form a honeynet.

          There are many advantages to honeypots. The main one is the ease with which they are employed. Another advantage is that although honeypots seek small amounts of hacker information, the information is considered highly valuable for studying and uncovering hackers' motivations.

Honeypot systems are not perfect, however. They contain the usual technology risks such as firewall penetration, broken encryption methods and failure to detect attacks. In addition, honeypots are unable to detect attacks against systems that are not honeypot systems.

There are two different kinds of honeypots. They are classified based on their deployment method:

• Production Honeypot: Used by companies and corporations for the purpose of researching the motives of hackers as well as diverting and mitigating the risk of attacks on the overall network.
• Research Honeypot: Used by nonprofit organizations and educational institutions for the sole purpose of researching the motives and tactics of the hacker community for targeting different networks.

Honeypots are not always designed to identify hackers. Honeypot developers are often more interested in getting into the minds of hackers, which then permits them to design more secure systems, as well as to educate other professionals about the lessons learned through their efforts. Overall, honeypots are considered an effective method to track hacker behavior and heighten the effectiveness of computer security tools.