Hacker
A computer hacker is any skilled computer expert that uses their technical knowledge to overcome a problem. While "hacker" can refer to any skilled computer programmer, the term has become associated in popular culture with a "security hacker", someone who, with their technical knowledge, uses bugs or exploits to break into computer systems
Definitions
General Definition
Reflecting the two types of hackers, there are two definitions of the word "hacker":
- an adherent of the technology and programming subculture; see hacker culture.
- someone who is able to subvert computer security. If doing so for malicious purposes, the person can also be called a cracker.

The controversy is usually based on the assertion that the term originally meant someone messing about with something in a positive sense, that is, using playful cleverness to achieve a goal. But then, it is supposed, the meaning of the term shifted over the decades and came to refer to computer criminals.[3]
As the security-related usage has spread more widely, the original meaning has become less known. In popular usage and in the media, "computer intruders" or "computer criminals" is the exclusive meaning of the word today. (For example, "An Internet 'hacker' broke through state government security systems in March.") In the computer enthusiast (Hacker Culture) community, the primary meaning is a complimentary description for a particularly brilliant programmer or technical expert. (For example, "Linus Torvalds, the creator of Linux, is considered by some to be a hacker.") A large segment of the technical community insist the latter is the "correct" usage of the word (see the Jargon File definition below).
Representation of Hackers in Mainstream Media

Representation of Hackers in Network News
However, network news use of the term consistently pertained primarily to the criminal activities, despite the attempt by the technical community to preserve and distinguish the original meaning, so today the mainstream media and general public continue to describe computer criminals, with all levels of technical sophistication, as "hackers" and do not generally make use of the word in any of its non-criminal connotations. Members of the media sometimes seem unaware of the distinction, grouping legitimate "hackers" such as Linus Torvalds and Steve Wozniak along with criminal "crackers".[4]
As a result, the definition is still the subject of heated controversy. The wider dominance of the pejorative connotation is resented by many who object to the term being taken from their cultural jargon and used negatively,[5] including those who have historically preferred to self-identify as hackers. Many advocate using the more recent and nuanced alternate terms when describing criminals and others who negatively take advantage of security flaws in software and hardware. Others prefer to follow common popular usage, arguing that the positive form is confusing and unlikely to become widespread in the general public. A minority still use the term in both senses despite the controversy, leaving context to clarify (or leave ambiguous) which meaning is intended.
However, because the positive definition of hacker was widely used as the predominant form for many years before the negative definition was popularized, "hacker" can therefore be seen as a shibboleth, identifying those who use the technically-oriented sense (as opposed to the exclusively intrusion-oriented sense) as members of the computing community. On the other hand, due to the variety of industries software designers may find themselves in, many prefer not to be referred to as hackers because the word holds a negative denotation in many of those industries.
A possible middle ground position has been suggested, based on the observation that "hacking" describes a collection of skills and tools which are used by hackers of both descriptions for differing reasons. The analogy is made to locksmithing, specifically picking locks, which is a skill which can be used for good or evil. The primary weakness of this analogy is the inclusion of script kiddies in the popular usage of "hacker," despite their lack of an underlying skill and knowledge base.
Sometimes, "hacker" is simply used synonymously with "geek": "A true hacker is not a group person. He's a person who loves to stay up all night, he and the machine in a love-hate relationship... They're kids who tended to be brilliant but not very interested in conventional goals[...] It's a term of derision and also the ultimate compliment."[6]
Fred Shapiro thinks that "the common theory that 'hacker' originally was a benign term and the malicious connotations of the word were a later perversion is untrue." He found that the malicious connotations were already present at MIT in 1963 (quoting The Tech, an MIT student newspaper), and at that time referred to unauthorized users of the telephone network, that is, the phreaker movement that developed into the computer security hacker subculture of today.
Types
Hacker culture

Security hackers are people involved with circumvention of computer security. Among security hackers, there are several types, including:
White hats are hackers who work to keep data safe from other hackers by finding system vulnerabilities that can be mitigated. White hats are usually employed by the target system's owner and are typically paid (sometimes quite well) for their work. Their work is not illegal because it is done with the system owner's consent.
Black hats or crackers are hackers with malicious intentions. They often steal, exploit, and sell data, and are usually motivated by personal gain. Their work is usually illegal. A cracker is like a black hat hacker,[13] but is specifically someone who is very skilled and tries via hacking to make profits or to benefit, not just to vandalize. Crackers find exploits for system vulnerabilities and often use them to their advantage by either selling the fix to the system owner or selling the exploit to other black hat hackers, who in turn use it to steal information or gain royalties.
Grey hats include those who hack for fun or to troll. They may both fix and exploit vulnerabilities, but usually not for financial gain. Even if not malicious, their work can still be illegal, if done without the target system owner's consent, and grey hats are usually associated with black hat hackers.
Motives

Overlaps and differences

According to Raymond, hackers from the programmer subculture usually work openly and use their real name, while computer security hackers prefer secretive groups and identity-concealing aliases.[16] Also, their activities in practice are largely distinct. The former focus on creating new and improving existing infrastructure (especially the software environment they work with), while the latter primarily and strongly emphasize the general act of circumvention of security measures, with the effective use of the knowledge (which can be to report and help fixing the security bugs, or exploitation reasons) being only rather secondary. The most visible difference in these views was in the design of the MIT hackers' Incompatible Timesharing System, which deliberately did not have any security measures.

The programmer subculture of hackers sees secondary circumvention of security mechanisms as legitimate if it is done to get practical barriers out of the way for doing actual work. In special forms, that can even be an expression of playful cleverness. However, the systematic and primary engagement in such activities is not one of the actual interests of the programmer subculture of hackers and it does not have significance in its actual activities, either. A further difference is that, historically, members of the programmer subculture of hackers were working at academic institutions and used the computing environment there. In contrast, the prototypical computer security hacker had access exclusively to a home computer and a modem. However, since the mid-1990s, with home computers that could run Unix-like operating systems and with inexpensive internet home access being available for the first time, many people from outside of the academic world started to take part in the programmer subculture of hacking.

All three subcultures have relations to hardware modifications. In the early days of network hacking, phreaks were building blue boxes and various variants. The programmer subculture of hackers has stories about several hardware hacks in its folklore, such as a mysterious 'magic' switch attached to a PDP-10 computer in MIT's AI lab, that when turned off, crashed the computer.[20] The early hobbyist hackers built their home computers themselves, from construction kits. However, all these activities have died out during the 1980s, when the phone network switched to digitally controlled switchboards, causing network hacking to shift to dialing remote computers with modems, when pre-assembled inexpensive home computers were available, and when academic institutions started to give individual mass-produced workstation computers to scientists instead of using a central timesharing system. The only kind of widespread hardware modification nowadays is case modding.
An encounter of the programmer and the computer security hacker subculture occurred at the end of the 1980s, when a group of computer security hackers, sympathizing with the Chaos Computer Club (which disclaimed any knowledge in these activities), broke into computers of American military organizations and academic institutions. They sold data from these machines to the Soviet secret service, one of them in order to fund his drug addiction. The case was solved when Clifford Stoll, a scientist working as a system administrator, found ways to log the attacks and to trace them back (with the help of many others). 23, a German film adaption with fictional elements, shows the events from the attackers' perspective. Stoll described the case in his book The Cuckoo's Egg and in the TV documentary The KGB, the Computer, and Me from the other perspective. According to Eric S. Raymond, it "nicely illustrates the difference between 'hacker' and 'cracker'. Stoll's portrait of himself, his lady Martha, and his friends at Berkeley and on the Internet paints a marvelously vivid picture of how hackers and the people around them like to live and how they think."
BY : HARSH SINGH NEGI
ConversionConversion EmoticonEmoticon