Mobile OS Security model comparision

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Transcript Mobile OS Security model comparision

Web based and network based attacks: The mobile
device is connected to the internet, browsing websites
with malicious content.
Malware: traditional viruses, worms and trojan horses.
Social engineering attacks: phishing. Also used to install
Resource and service availability abuse: botnet,
spamming, overcharging (SMS and calls).
Attacks on the integrity of the device’s data: malicious
encryption with ransom, modification of data such as
address book.
Traditional Access Control
Application Provenance
Permissions-based access control
Traditional Access Control: This mechanism seeks to protect
devices using techniques such as passwords and idle-time
screen locking.
Application Provenance: is an approach where each
application is stamped with the identity of its author and made
tamper resistant (eg: digital signature). Thus enabling a user to
decide to use or not to use the application based on the identity
of the author.
Encryption: is a approach to conceal data on the device to
address device loss or theft.
Isolation: limits applications ability to access sensitive data or
systems on a device.
Permission-based access control: grants set of permissions to
each application, limiting each application to access device
data/systems within the scope of the permission. Blocks the
application if it attempts to perform actions exceeding the
permissions given.
Apple iOS
 I OS provides traditional access control security options, which
include password configuration options such as account lockout
Example: The strength of the passcode can be chosen by the administrator
and the administrator can also specify how frequently the user can update
the passcodes, and the maximum number of failed login attempts before the
device wipes itself.
Android provides password configuration options, which include
specifying the strength of the device passcode, phone’s lockout time
span, failed login attempts before device wipes data, indication of
password expiration, enabling administrators to compel users to
update their passwords on a regular basis .
Apple’s iOS
 The access control feature of the iOS provides a reasonable level of
security for the devices data in the event of loss or theft.
 The iOS is in par with traditional windows based desktops in this
 The password policy system is sufficient to protect devices against
casual attacks.
 The previous versions of Android do not encrypt data stored on
removable SD memory card, thus allowing the attacker to eject the
SD memory card, and obtain the data by bypassing all password
Apple iOS
Before releasing the software to iPhone, iPod, and iPad users. The developer
goes through a registration process with apple and pay an annual licensing
fee. The developers then “digitally sign” each app with an apple-issued
digital certificate before its release. This signing process of the developer into
the app proves that the app author is an apple-approved developer and the
app’s logic cannot be tampered with after its creation by the developer.
Through App Store
The developer submits the app for a cerifitcation by apple – approval process
takes one or two weeks and then the app is deployed into the app store.
If the app is found malicious or any violation of license agreement occurs,
the app is removed from the appstore, but no automated mechanism has been
implemented to remove the app from the devices (iphone/ipad) after it has
been installed.
Google undermines both the goals of ensuring that the app’s logic is
not tampered with and to allow the user of the app to determine the
identity of the app’s author.
 Android OS only installs and runs apps that have been properly
signed with a digital cerificate. Unlike apple software developers
need not apply to google to obtain a code-signing certificate, thus the
developer can generate their own signing certificates.
 This results in an malware author generating anonymous digital
certificate, and no certificate or malware signed with google that can
be tracked back to the author.
Through google’s android market
 For developers to sell their apps on android marketplace, a 25$ fee is
charged via credit card, thus allowing google to associate the payee
with the digital ceritificate, which may reduce the chances of
distribution of malicious apps (if the developer uses his own credit
Apple iOS
 Apple’s approach is effective as
The developer must register and pay to obtain a signing certificate
from apple, which makes it more easy to identify if any malicious
activities are performed.
Each and every application is tested before submission to the appstore.
Apple’s code signing model prevents tampering with published
 Since no single authority evaluates or verifies all Android apps,
attackers are more likely to release attacks without worrying of
getting caught.
Apple iOS
The iOS uses a hardware accelerated AES-256 encryption to encrypt
all data stored in the flash memory of the device.
The iOS protects specific additional data items, such as email using
an additional layer of encryption.
Within 10 seconds of the device locking, the decryption keys for files
in device are discarded.
Android recently began offering built in encryption in 3.0, earlier
versions of android contain no encryption capability, instead to rely
on islolation and permissions to safeguard data. A simple jailbreak of
an android phone, or theft of device’s SD card can lead to significant
loss of data.
Apple iOS
iOS operating system isolates each app from every app on the system.
The apps are not allowed to modify or view each other’s data, or even
know if other apps exist on the OS, nor can they access the OS
kernel, nor install privileged driver’s or obtain root level
administrator access to the device.
The apps are also isolated from the phone’s SMS, email in-out box
and other email attachments.
Like iOS, Android employs a strong isolation system. It not only
isolates apps from each other but also prevents apps from accessing
or modifying the OS kernel, ensuring the app doesn’t get admin
control over a device.
Blackberry (BB10):
introduces us to Blackberry Balance. Balance allows organizations to
create isolation between personal and work environments on a device.
Additional logical security is used to keep personal applications, files
and network separate from the work environment.
When Balance is enabled, workspace is automatically encrypted,
leaving personal environment unencrypted.
Windows Phone 8:
WP8 uses the Unified Extensible Firmware Interface for secure boot,
ensuring devices do not load rooted or unauthorized system images.
WP8 apps run in isolated “chambers”, which are similar to sandbox.
Chambers keep applications and their data separate from one another.
The data between the applications is shared in the cloud and not on
the device.
Apple iOS
The iOS denies access under all circumstances to many of the
device’s sensitive subsystems. Thus increasing the security of iOS
based devices since it removes the user from security decisionmaking process.
The above process also limit’s each applications functionality,
potentially limiting the utility of certain classes of iOS apps.
The Android permission system relies on the user to make all policy
decisions and decide whether an apps requested combination of
permission is safe or not.