Monday 12 March 2012

ETHICAL HACKING
The term "white hat" in Internet slang refers to an ethical hacker, or a computer security expert, who specializes in penetration testing and in other testing methodologies to ensure the security of an organization's information systems. Ethical hacking is a term coined by IBM meant to imply a broader category than just penetration testing. White-hat hackers are also called "sneakers", red teams, or tiger teams.

HISTORY OF HACKING

One of the first instances of an ethical hack being used was a “security evaluation” conducted by the United States Air Force of the Multics operating systems for "potential use as a two-level (secret/top secret) system." Their evaluation found that while Multics was "significantly better than other conventional systems," it also had "... vulnerabilities in hardware security, software security, and procedural security" that could be uncovered with "a relatively low level of effort." The authors performed their tests under a guideline of realism, so that their results would accurately represent the kinds of access that an intruder could potentially achieve. They performed tests that were simple information-gathering exercises, as well as other tests that were outright attacks upon the system that might damage its integrity. Clearly, their audience wanted to know both results. There are several other now unclassified reports that describe ethical hacking activities within the U.S. military.[4] The idea to bring this tactic of ethical hacking to assess security of systems was formulated by Dan Farmer and Wietse Venema. With the goal of raising the overall level of security on the Internet and intranets, they proceeded to describe how they were able to gather enough information about their targets to have been able to compromise security if they had chosen to do so. They provided several specific examples of how this information could be gathered and exploited to gain control of the target, and how such an attack could be prevented. They gathered up all the tools that they had used during their work, packaged them in a single, easy-to-use application, and gave it away to anyone who chose to download it. Their program, called Security Analysis Tool for Auditing Networks, or SATAN, was met with a great amount of media attention around the world.

Thursday 8 March 2012

ARPANET

  

                              ARPANET

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ARPANET logical map, March 1977

The Advanced Research Projects Agency Network (ARPANET), was the world's first operational packet switching network and the core network of a set that came to compose the global Internet. The network was funded by the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense for use by its projects at universities and research laboratories in the US. The packet switching of the ARPANET was based on designs by Lawrence Roberts of the Lincoln Laboratory.[1]

Packet switching, today the dominant basis for data communications worldwide, was a new concept at the time of the conception of the ARPANET. Prior to the advent of packet switching, both voice and data communications had been based on the idea of circuit switching, as in the traditional telephone circuit, wherein each telephone call is allocated a dedicated, end to end, electronic connection between the two communicating stations. Such stations might be telephones or computers. The (temporarily) dedicated line is typically composed of many intermediary lines which are assembled into a chain that stretches all the way from the originating station to the destination station.

With packet switching, a data system could use a single communications link to communicate with more than one machine by collecting data into datagrams and transmitting these as packets onto the attached network link, as soon as the link becomes idle. Thus, not only can the link be shared, much as a single post box can be used to post letters to different destinations, but each packet can be routed independently of other packets.