Reverse Engineering, Reverse Engineering

The same techniques are currently being researched for application to legacy software systems, not for industrial or defense ends, but rather to replace incorrect, incomplete, or otherwise unavailable documentation A Survey of Reverse Engineering and Program Comprehension. Michael L. Nelson, April 19, 1996, ODU CS 551 - Software Engineering Survey.

Reverse engineering is a process of examination only: the software system under consideration is not modified (which would make it reengineering). Software anti-tamper technology is used to deter both reverse engineering and reengineering of proprietary software and software-powered systems. In practice, two main types of reverse engineering emerge. In the first case, source code is already available for the software, but higher-level aspects of the program, perhaps poorly documented or documented but no longer valid, are discovered. In the second case, there is no source code available for the software, and any efforts towards discovering one possible source code for the software are regarded as reverse engineering. This second usage of the term is the one most people are familiar with. Reverse engineering of software can make use of the Cleanroom Software Engineering technique to avoid infringing copyrights.

An example of a group that reverse-engineers software for enjoyment is CORE which stands for "Challenge Of Reverse Engineering". In the United States, the Digital Millennium Copyright Act (DMCA) exempts from the circumvention ban some acts of reverse engineering aimed at interoperability of file formats and protocols, but judges in key cases have ignored this law, since it is acceptable to circumvent restrictions for use but not for access.

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