A. Model Defense Techniques and Mechanisms: It is the smartphone OS security model defense capabilities and methods. This is discussed in the sections of iOS and Android security models. The techniques are approximately similar but: • With difefrent degree of effectiveness: the sandboxing, which iOS is more effective than Android. • With difefrent tools used: for the memory protection, the iOS uses ASLR compared to Android which uses MMU and ASLR starting from V4. Also for the code protection DEP used in iOS. However, Android uses Java Safety Type and DEP starting from V2.3. • With difefrent numbers of tools: the antivirus tools are more available for Android than iOS and this is explained by the strict restrictions of iOS Apps and the antivirus couldn't freely scan malwares. The different mechanisms are the permissions used with Android and the data encryption used with iOS. Lastly, the Android provide components protection which is suitable for its architecture.
B. Vulnerabilities: The comparisons under this criteria is stated by [8]. First two sub criteria, tools availability and friendliness development encourage the developers to develop new Apps. But from the security point of view those aspects are vulnerabilities because they provide more facilities for the hackers. Android provides them but iOS doesn't but only with partial availability of tools. One could conclude that, this availability and friendliness of developments explained by the large numbers of threats and mal wares for Android. Second two sub criteria are the installation
options and Apps market type. Those also enhance the flexibility of smartphone but violate the security. There are restricted options for installation in iOS compared to multi in Android. Also one official repository compared to one official plus many unofficial in Android. These security issues comes from facilitating the installation of mal wares in the smartphones. Last point is the compatibility, which is vulnerable in both iOS and Android.
C. Strengths: The literature in [8,3] stated a list of comparable points and we will study them in our case. One important mechanism used by iOS but not Android is the Apps reviewing. It provides protection from installing malicious mal wares in the official market. They are equal by providing remotely deletion of detected malicious Apps. The cost of distribution is other security advantage hinders the attacker from adding their mal wares into repository. Again this is achieved by iOS but not Android. Other measurement is the API protection and here the Android provides it. The Apps signing, the authentication, and the availability of certificates (Federal Information Processing Standard (FIPS) 140-2) are mechanisms in both iOS and Android. Firewall as a security famous tool is neither iOS nor Android built-in. The virtualization is applied in both OSs but with two different points of view. Device wipe and keychain are others security measures. Device wipe applied locally and remotely in iOS but less in Android. In Android only possible way to apply remotely. The keychain is used in iOS but not in Android. Lastly the email protection, iOS has a secure Email compared to Android.
D. Security Applications: The security applications or what is known as antivirus applications are more available for Android than iOS and this could explained by what we mentioned about the strict restrictions of iOS applications and the openness of Android compared to iOS. This is clear, just one (Lookout Mobile Security) antivirus tool for iOS and six for Android [20].
E. implemented Solutions: One good thing about the development facilities, which we have criticized, is that Android has the advantage of implementing practical solutions for the different security threats. The restricted development in iOS provides less help in implementing solutions. Forty two solutions for Android are implemented against only seventeen for iOS [20].
F Rating: Last criteria is the referring to other scientific studies and reports to rate the security of iOS vs. Android. [22] gives 3.4 out of 5 for iOS compared to 3 for Android (V3, 4) and [2] gives 1.7 out of 5 for iOS (V5) faced by l.37 for Android (V2.3). These ratings give a little surpass to iOS against Android.