KEYGEN

Key Generator (zharg. кейген, kigen) (on pp. Keygen, key generator) - a small program that generates: 
cryptographic key to encrypt data. 
psevdopodlinnye CD-keys or serial / registration / activation numbers for registration / activation software. 

Teams that specialize in hacking software offer them at various sites dedicated to the spread of free software license compliance. Because the majority of licensed software that uses activation keys require mandatory purchase code, the use of unpaid keygenov for proprietary software is usually illegal [source?]. Some of the copyright (eg, DMCA in 1998 in the U.S. and the fourth part of the Civil Code of 2006 in Russia) explicitly prohibit the circumvention of TSZAP.
The operating principle of the generator switches 

Typically, the key used during installation. Software installer uses algebraic computation to the input key to verify it for authenticity. For example, the algorithm must determine that the input key should contain 5 numbers, the amount equal to 25 and that the key should also contain 3-5 letters so that, after translating them into numerical equivalents in the amount we get 42. 

To write the same кейгена, the author typically uses dizassambler to view the source code program in assembly language, which is written кейген checking how alone and installer. When he gets access to the code of the program, it determines the function, which is responsible for verifying the authenticity of the input key. Due to this, he can write an algorithm used to generate the true keys to be included in кейген.
Problems keygenov 

Besides legal problems, there are two main difficulties when using keygenov: product activation and online validation key. 

Keys generated keygenom may not work if the program is used in the network, including also download the updates. This is due to the fact that the user must confirm their serial number each time a program connects to the server, and the key may be incorrect for various reasons. 

One reason is that the attacker may wrongly understand the original algorithm, which was «good enough», to install the software, but do not do all the correct keys are generated. 

Another reason is that the developers allow the keys, which they knew were distributed to media representatives during the development, or have been issued for the registration of the network, leading to what is cryptographically correct key is not genuine. 

A third reason may be unpublished algorithm used by the seller. In addition to the previous example, the symbols 0, 1, 9, P and K will not be accepted. The program, which verifies the key on the computer user is unaware of these restrictions and will input the key, but the online verification has not been confirmed. 

Keys to MMO games are different. Typically, each key is unique and comes with the product in a protected form in the envelope or card with a washable cover. Typically, keys are associated with gaming account after use, leading to further futility. Therefore, the MMORPG is usually not the subject of piracy. 

Also, кейгены may contain viruses (depending on their place of downloading). When the program opened, instead of to ensure that the correct key, it can install malicious software on the user's computer.

KEYGEN