Security hacker another crime such as destroying information contained in that system". These subgroups may also be defined by the legal status of their activities. A white hat hacker breaks security for non-malicious reasons, either to test their own security system, perform penetration tests, or vulnerability assessments for a client - or while working for a security company which makes security software. The term is generally synonymous with ethical hacker, and the EC-Council, among others, have developed certifications, courseware, classes, and online training covering the diverse arena of ethical hacking. A "black hat" hacker is a hacker who "violates computer security for
Prefix sum are calculated in the first pass on each processing unit; the prefix sum of these partial sums is then calculated and broadcast back to the processing units for a second pass using the now known prefix as the initial value. Asymptotically this method takes approximately two read operations and one write operation per item. When a data set may be updated dynamically, it may be stored in a Fenwick tree data structure. This structure allows both the lookup of any individual prefix sum value and the modification of any array value in logarithmic time per operation.. However, an earlier 1982