Content filtering is the process of managing or screening access to specific emails or web pages. The purpose is to block content containing harmful information. Content filtering programs are commonly used by organizations to control access to content through their firewalls. Home computers can also be used.
Regarding this software and hardware work by identifying and blocking access to specific content or websites. A good example of how content filtering works is to point out specific patterns in the content, such as text strings or objects in images that indicate the presence of unwanted content. Content filters typically use keywords to block access to web pages, and in some cases, entire websites.
How we stop abuse spam phishing fraud and those kind of things. Using two things, content filtering and policy. Now content filtering is when you’re looking at the content for bad stuff. It might be when you are downloading a virus from a website and when someone’s sending you a spam message and you look at the payload or the content of that message. You try to figure out if that payload or content is bad. This has been the traditional method of filtering bad stuff for a long time. Now, this is great and this is something that content filtering application absolutely does but this by itself isn’t the whole solution. There’re lots of ways where you may not have any information about the kind of content that’s malicious and you still need to try to work out if this is possible to filter out potential threats.
We have what’s called policy which is something that looks at reputation or behavior of what people are doing. If you look at the way that people behave, you can determine that they’re behaving maliciously even if you don’t know that the content or the payload is bad. The way that we can do that, for example, is there’re some very simple things like volumetric: one person might send one message to another person and that’s fine; but with one person sending thousands of messages to another person, that’s potentially an issue. Just send it to one person but they send it to a different person with every single message. That’s a really simple example. Another one in the mobile world is If you are sending a message to somebody, you’ll typically get replies from the person that you’re receiving messages from. Now that’s in a normal behavior, but if you’re a spammer or a bad guy then typically you’ll send lots of messages to lots of different phones and those people won’t reply to you because they’re not your friends. In fact they’re probably deleting that message. You sent to them but got no reply, because it was malicious. So again we can detect the threat because we can look at the behavior of a certain mobile phone and say well this guy typically sends a lot of messages never gets replies from those people. Hence we can set up a policy targeting such behaviors.
So that’s behavioral analysis. The reason that this is important is if you have behavioral analysis and content analysis you can really detect 99% of all the threats out there. One or the other you’re detecting may be 60 or 70 percent of the threats. So there’s a big difference between using both of those and typically using behavioral analysis is much better on your infrastructure. It requires less processing power which means that you don’t require as much of a large solution. It’s much more cost-effective. So if you’re buying a solution to stop abuse, to stop spam, and to stop fraud etc., look for solutions that’s got content filtering and policy or behavior analysis and that will give you the best solution.
Along the same line, organizations or governments can step up their game by employing even more sophisticated content filtering systems with artificial intelligence in the mix. A case in point is China’s Great Firewall content censorship system that combines legal frameworks and technological means to block certain content the Chinese government deems inappropriate for their country. To help determine how effective such mechanism is, specialized services such as GoClick China have created testing tools to check if websites or applications are being filtered and blocked in China. Check the tool out and get a first-hand experience how to know whether content filtering is effective or not.