Editing Product key (section)

==Effectiveness==
Standard key generation, where product keys are generated mathematically, is not completely effective in stopping [[copyright infringement of software]], as these keys can be distributed. In addition, with improved communication from the rise of the [[Internet]], more sophisticated attacks on keys such as [[Software cracking|cracks]] (removing the need for a key) and [[Keygen|product key generators]] have become common.

Because of this, software publishers use additional [[product activation]] methods to verify that keys are both valid and uncompromised. One method assigns a product key based on a unique feature of the purchaser's computer hardware, which cannot be as easily duplicated since it depends on the user's hardware. Another method involves requiring one-time or periodical validation of the product key with an internet server (for games with an online component, this is done whenever the user signs in). The server can deactivate unmodified client software presenting invalid, duplicated, missing or otherwise compromised keys. Modified clients may bypass these checks,<ref>{{cite book |last1=Chang |first1=Hoi |last2=Atallah |first2=Mikhail J. |date=2002 |title=Security and Privacy in Digital Rights Management |chapter=Protecting Software Codes by Guards |url=https://doi.org/10.1007/3-540-47870-1_10 |publisher=Springer |page=160-175 |doi=10.1007/3-540-47870-1_10 |isbn=978-3-540-47870-6}}</ref> but the server can still deny those clients information or communication.