What Is the Difference Between a Hacker and a Cracker?
There have been many articles written (particularly on the Internet) about the difference between hackers and crackers. In them, authors often attempt to correct public misconceptions. This chapter is my contribution in clarifying the issue.

For many years, the American media has erroneously applied the word hacker when it really means cracker. So the American public now believe that a hacker is someone who breaks into computer systems. This is untrue and does a disservice to some of our most talented hackers.

There are some traditional tests to determine the difference between hackers and crackers. I provide these in order of their acceptance. First, I want to offer the general definitions of each term. This will provide a basis for the remaining portion of this chapter. Those definitions are as follows:

A hacker is a person intensely interested in the arcane and recondite workings of any computer operating system. Most often, hackers are programmers. As such, hackers obtain advanced knowledge of operating systems and programming languages. They may know of holes within systems and the reasons for such holes. Hackers constantly seek further knowledge, freely share what they have discovered, and never, ever intentionally damage data.

A cracker is a person who breaks into or otherwise violates the system integrity of remote machines, with malicious intent. Crackers, having gained unauthorized access, destroy vital data, deny legitimate users service, or basically cause problems for their targets. Crackers can easily be identified because their actions are malicious.
These definitions are good and may be used in the general sense. However, there are other tests. One is the legal test. It is said that by applying legal reasoning to the equation, you can differentiate between hackers (or any other party) and crackers. This test requires no extensive legal training. It is applied simply by inquiring as to mens rea.

Mens Rea
Mens rea is a Latin term that refers to the guilty mind. It is used to describe that mental condition in which criminal intent exists. Applying mens rea to the hacker-cracker equation seems simple enough. If the suspect unwittingly penetrated a computer system--and did so by methods that any law-abiding citizen would have employed at the time--there is no mens rea and therefore no crime. However, if the suspect was well aware that a security breach was underway--and he knowingly employed sophisticated methods of implementing that breach--mens rea exists and a crime has been committed. By this measure, at least from a legal point of view, the former is an unwitting computer user (possibly a hacker) and the latter a cracker. In my opinion, however, this test is too rigid.