mecha mecca

[Vampirosik...:)))]

Regular expressions are not very efficient and
[url= http://listtodo.org/setting/teen/index.html]therefore[/url] most IDS try to avoid testing the payload for a large number of regular expressions. To achieve that, an IDS would first use an efficient parallel matching algorithm such as Aho-Corasick, which is super fast and uses a single cycle through the payload to check for all signatures. In the other hand parallel matching can only matches simple strings. Only if a certain simple string matches, a follow-up regular expression is tested.To r
educe the number of regular expression tests required, the parallel matching algorithm searched the longest constant string extracted from every regular expression.
Unfortunately the regular expressions presented so far in this write-up do not have any fixed string in them as the look for a sequence of digits. Parallel matching algorithms can be adapted to search efficiently for a string of character groups, digits in this case, rather than a string of characters, but normal implementations found in most IDS do not support it.