A crackme (often abbreviated by cm) is a small program designed to test a programmer's reverse engineering skills. They are programmed by other reversers as a legal way to crack software, since no

intellectual property Intellectual property (IP) is a category of property that includes intangible creations of the human intellect. There are many types of intellectual property, and some countries recognize more than others. The best-known types are patents, cop ...

is being infringed upon. Crackmes, reversemes and keygenmes generally have similar protection schemes and algorithms to those found in proprietary software. However, due to the wide use of packers/protectors in commercial software, many crackmes are actually more difficult as the algorithm is harder to find and track than in commercial software.

Keygenme

A keygenme is specifically designed for the reverser to not only find the protection algorithm used in the application, but also write a small

keygen A key generator (key-gen) is a computer program that generates a product licensing key, such as a serial number, necessary to activate for use of a software application. Keygens may be legitimately distributed by software manufacturers for lice ...

for it in the programming language of their choice. Most keygenmes, when properly manipulated, can be self-keygenning. For example, when checking, they might generate the corresponding key and simply compare the expected and entered keys. This makes it easy to copy the key generation algorithm. Often anti-debugging and anti-disassemble routines are used to confuse debuggers or make the disassembly useless. Code-obfuscation is also used to make the reversing even harder.

References

External links

tdhack.com
- Includes cryptographic riddles, hackmes and software applications to crack for both

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ser ...

and

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...

Polish Polish may refer to: * Anything from or related to Poland, a country in Europe * Polish language * Poles Poles,, ; singular masculine: ''Polak'', singular feminine: ''Polka'' or Polish people, are a West Slavic nation and ethnic group, w ...

and

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

languages are supported.
Ollydbg
- A program used both by beginners and experienced people. Computer security Software cracking Reverse engineering {{programming-software-stub