i would like to do my doctorate degree(Ph.D) in network security particularly. can you help and give tips the topics and to do so...
please...

welcome

I would suggest as a starting point that you go to http://en.wikipedia.org/wiki/Network_security and learn the definition of all the terms you find there. Any time you are challenged regarding the meaning of a term, gain consensus on the proper definition; especially with your school's teaching hierarchy. Challenge, don't accept - the industry is changing too quickly for teachers to keep up. Part of your challenge is bringing them along with you in developing your thesis. By the time you present, you should know what they expect because you have managed their expectations.

thank you for your suggestion towards network security. its interesting to read the thing in you suggested URL.

Anyone with aspirations of completing a doctorate really ought to:

a) have a passion for the subject. If you had this, you wouldn't be asking this kind of question.
Your approach of "I want to do a Ph.D" seems to be about the same as "I'm off down to walmart to get some beans, what brand should I get?".

b) Just how did you get this far without having to think for yourself? Your Bachelor degree should have prepared you for this (unless you got that from the internet as well, and hoping for the same easy ride to a PhD).
A PhD ends in a thesis containing new and original work (requiring new and original thought from you). At least a PhD which is worth anything would require it.

Thus far, you've shown no sign at all that you're even capable of a google search,

to whit...
> its interesting to read the thing in you suggested URL.
Oh boy.
You mean you didn't think to get there by yourself, and you're amazed by what you find there?

network security is much of a science in its own
to develop a PhD research on it as said before. you must have the passion

anyways if u took VPN Security systems in concern it would be easy to start with

Right on Salem!

Yo, PhD Candidate Yenesky, choose at least 3 approaches then ask for a poll/suggestion on what is better/more relevant/more timely.

That way, you can prove your passion and your ability to undertake preliminary research. And you are just taking a poll for the best approach/focus to take.