What is Hacking?

Computer in dark office, security alert on screen
Getty Images/Dimitri Otis

In computer networking, hacking is any technical effort to manipulate the normal behavior of network connections and connected systems. A hacker is any person engaged in hacking. The term "hacking" historically referred to constructive, clever technical work that was not necessarily related to computer systems. Today, however, hacking and hackers are most commonly associated with malicious programming attacks on the Internet and other networks.

Origins of Hacking

M.I.T. engineers in the 1950s and 1960s first popularized the term and concept of hacking. Starting at the model train club and later in the mainframe computer rooms, the so-called "hacks" perpetrated by these hackers were intended to be harmless technical experiments and fun learning activities.

Later, outside of M.I.T., others began applying the term to less honorable pursuits. Before the Internet became popular, for example, several hackers in the U.S. experimented with methods to (illegally) modify telephones for making free long-distance calls over the phone network.

As computer networking and the Internet exploded in popularity, data networks became by far the most common target of hackers and hacking.

Well-Known Hackers

Many of the world's most famous hackers began their exploits at a very young age. Some were convicted of major crimes and served time for their offenses.

To their credit, some of them also rehabilitated and turned their skills into productive careers.

More: Famous Crimes and Criminals on Computer Networks and the Internet

Hacking vs. Cracking

While true hacking applies only to activities having good intentions, malicious attacks on computer networks are officially known as cracking.

Most non-technical people fail to make this distinction, however. It is extremely common to see the term "hack" misused and be applied to cracks as well.

Common Network Hacking Techniques

Hacking on computer networks is often done through scripts and other network software. These specially-designed software programs generally manipulate data passing through a network connection in ways designed to obtain more information about how the target system works. Many such pre-packaged scripts are posted on the Internet for anyone - typically entry-level hackers - to use. More advanced hackers may study and modify these scripts to develop new methods. A few highly skilled hackers work for commercial firms, hired to protect that company's software and data from outside hacking.

Cracking techniques on networks include creating worms, initiating denial of service (DoS) attacks, or in establishing unauthorized remote access connections to a device.

Effective hacking requires a combination of technical skills and personality traits:

  • ability to work with numbers and a background in mathematics. Hacking often requires sorting through large amounts of data, code and computer algorithms.
  • memory recall and logical reasoning. Hacking involves assembling small facts and details (sometimes from many sources) into a plan of attack based on the logic of how computer systems work.
  • patience. Hacks tend to get very complex and requite large amounts of time to plan and execute).