Apart from that speed-wise is reg-exp matching still much faster than
simple sring matching like Bayer-moore or similar algos ??
Regular expression matching is comparable in speed to simple string
matching, and (generally) slower than Boyer-Moore *for single strings*.
Where it can gain performance is that it can efficiently match a lot of
strings in parallel. Robin Sommer & I are now working on using this to
significantly enhance Bro's signature-matching capabilities - stay tuned.
how about the multi-pattern matching algorithms?
I think the multi-pattern matching algorithms may be a well choice to solve the signatures matching problems in IDS.
use these algorithms, we can match multi-signatures in parallel.