Why is linux so secure?
I was perusing the Linux Forum one day and came across this question with an excellent answer from "mr98ai". I asked his permission to place his response here on my WebSite cause I thought is was excellent. Short and to the point.
For a start, an application in linux needs certain permissions to complete a specified task. In that way, an application can become off-limits to ordinary users, but totally accessible to the administrator of the system. This protects the system from being changed by a user who doesn't know or understand what (s)he is doing. If a virus is trying to run, but is being run by an ordinary user, that virus will only be able to damage what an ordinary user can damage; his or her own files and settings. The rest of the system, the virus cannot change because it does not have permission, for example, to delete kernel files, modules, or important settings.
Secondly, because of the nature of open source, many people from all over the world can look at the source code, and suggest improvements and bug fixes. Any bugs or security holes would probably soon be uncovered by hackers and crackers, especially because those intent on doing evil can easily find out where to attack, simply by looking at the source code. The bugs are usually quickly rooted out.
Thirdly, Linux was built "on" the internet; it knows the internet exists, and it knows how to deal with it. Window's was not built with the internet in mind. Many bad designs (activeX comes to mind) were incorporated simply because the designers did not account for internet / intranet. For backwards compatibility (among other reasons), it is too late to go back now.
Fourthly, linux is much harder to install / operate on a day to day basis than windows. This automatically determines the type of user using linux... one who knows a lot about computers, how they function, what not to do etc, basically, the user is much more aware of what he / she and their computer is doing.
Linux is not just about security, although that is a huge thing in and of itself. Did you know that windows longhorn (the latest development version of windows) will not execute any program unless it is signed by Microsoft? What kind of crap is that? It's MS's way of dealing with security. The solution is not to try and stamp every valid program with an approved signature, but is to prevent applications from executing unless it has the necessary user permissions. The difference is subtle, but yet so large. A cracker will probably have no trouble forging a signature from MS, and then having free reign of your computer. Not only will this signature thing be a pain in the you-know-what, it is also very offensive... MS taking control of my life, what I can do, what I can't, treating me like a little ignorant child. So you see, the other side of linux is freedom.
That's all that comes to my mind right now. I am sure a linux expert could tell you more.
I don't think a Linux expert would really say much more.