Daniel Hruska Gatekeeper is one of the main features that will make its debut in the upcoming OS X Mountain Lion. Its purpose is (literally) to guard the system and only allow applications that meet certain criteria to run. Is this the ideal way to prevent malware?
In Mountain Lion, that "security plane" is divided into three levels, namely applications will be allowed to run if they are
- Mac App Store
- Mac App Store and from well-known developers
- any source
Let's take the individual options in order. If we look at the first one, it is logical that only a very small percentage of users will choose this path. Although there are more and more applications in the Mac App Store, it is far from having such a range that everyone can get by with this source alone. Whether Apple is moving towards a gradual locking of OS X with this step is a question. However, we prefer not to engage in speculation.
Immediately after installing the system, the middle option is active. But now you may ask yourself who is the well-known developer? This is someone who has registered with Apple and received their personal certificate (Developer ID) with which they can sign their applications. Every developer who hasn't done so yet can get their ID using a tool in Xcode. Of course, no one is forced to take this step, but most developers will want to ensure that their applications run smoothly even on OS X Mountain Lion. No one wants their application to be rejected by the system.
Now the question is, how does one even sign such an application? The answer lies in the concepts of asymmetric cryptography and electronic signature. First, let's briefly describe asymmetric cryptography. As the name suggests, the whole process will take place differently than in symmetric cryptography, where one and the same key is used for encryption and decryption. In asymmetric cryptography, two keys are needed – private for encryption and public for decryption. I understand key is understood to be a very long number, so that guessing it by the "brute force" method, i.e. by successively trying all possibilities, would take a disproportionately long time (tens to thousands of years) given the computing power of today's computers. We can talk about numbers typically 128 bits and longer.
Now to the simplified principle of electronic signature. The holder of the private key signs his application with it. The private key must be kept secure, otherwise anyone else could sign your data (eg an application). With data signed in this way, the origin and integrity of the original data is guaranteed with a very high probability. In other words, the application comes from this developer and has not been modified in any way. How do I verify the origin of the data? Using a public key that is available to anyone.
What ultimately happens to an application that does not meet the conditions in the previous two cases? In addition to not launching the application, the user will be presented with a warning dialog box and two buttons – Zrušit a Delete. Pretty tough choice, right? At the same time, however, this is a genius move by Apple for the future. As the popularity of Apple computers increases every year, they too will eventually become a target for malicious software. But it is necessary to realize that the attackers will always be one step ahead of the heuristics and capabilities of antivirus packages, which also slow down the computer. So there is nothing easier than allowing only verified applications to run.
For now, however, there is no imminent risk. Only a small amount of malware has appeared in recent years. Potentially harmful applications could be counted on the fingers of one hand. OS X is still not widespread enough to become a primary target for attackers who target Windows operating systems. We won't lie to ourselves that OS X isn't leaky. It is just as vulnerable as any other operating system, so it is better to nip the threat in the bud. Will Apple be able to eliminate the threat of malware on Apple computers for good with this step? We'll see over the next few years.
The last option of Gatekeeper does not bring any restrictions regarding the origin of the applications. This is exactly how we've known (Mac) OS X for over a decade, and even Mountain Lion doesn't have to change anything about it. You will still be able to run any applications. There is plenty of excellent open source software to be found on the web, so it would certainly be a shame to deprive yourself of it, but at the cost of reduced security and increased risk.
