Mobile Application Security: Best Practices for App Developers

The mobile application market is growing at an exponential rate. Thousands of new applications are added to the market every single day. The apps downloaded today entertain the user, help them connect and socialize with people in the vicinity and also share details about their lives and photos online.

These applications allow us to do everything from mobile banking, shopping to controlling automated home technology. In 2018, nearly 200 billion apps were downloaded worldwide. By 2020, it is said the apps industry alone will generate about $190 billion, if not more.
Source: https://www.statista.com/topics/1002/mobile-app-usage/
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Everything is done online and unfortunately this technological upgrade means a lot of personal user activity and information is vulnerable. Data like a user’s address, contact number and sometimes even location apart from banking information and credit card details are within the apps.
A single lapse in security and all this information is available to the cybercriminals and hackers. Ensuring this data’s security is key and the responsibility of the same must be taken by the app development company. ​

Why is App Security Important?
Data exploitation is a serious concern with the growing use of mobile apps. Businesses today have realized that they need to protect their user’s data and safeguard it against associated risks in order to ensure continued business productivity.
App security is a bare necessity and must not be treated like a bonus feature offered to the users. Users want safe environments as they are more aware of the threats and risks that come with using these apps. Hence it is safe to say the success of the app depends on the security it has.
One breach could end up losing the company money, but more importantly their users trust. This is why security must be a priority from the moment the developer starts writing the code.

How to Build a Secure App?
As apps are being used is a variety of ways, developers need to come up with equally different ways to defend the same. Keeping in mind the nature and sensitivity of user information, everything that can be done, must be done to help protect the clients. Given below are a few ways developers can build security into their apps:

Write a Secure Code
If the code has bugs and vulnerabilities, attackers can break into any application at the starting point itself. Research has shown that malicious code affects over 11.6 million mobile devices at any given time.
(Source: https://www.infosecurity-magazine.com/news/mobile-malware-infects-millions-lte-spurs-growth/)
The developer needs to reinforce the code from day one so it cannot be reverse engineered. Repeated tests must be carried out and the code must be easy to update and patch. An agile code makes it possible to update rectifications at a user’s end, post a breach.

Code Obfuscation
Obfuscation is the act of deliberately creating a code which is difficult for hackers to understand and hence cannot be reverse engineered. A developer can use this to hide the codes purpose, logic and values rooted in it. This can be done manually by the developer or by a machine.
Some examples of code obfuscation include:

• Renaming obfuscation: Altering the names of the methods and makes the source harder for a hacker to find or understand. Name obfuscation is a transformation used by most like .NET, iOS, Java and Android obfuscators.
• Control flow obfuscation: This yields non-deterministic semantic results when decompiled as it synthesizes conditional, branching and iterative constructs which produce an executable logic.
• Instruction pattern transformation: The constructs become less obvious as common instructions are converted by this technique.
• Dummy code insertion:A code which does not affect the logic of the program, is inserted, to make the reverse engineered code more difficult to analyse.
• Unused code and metadata removal: Removing debugging information and used code from the application makes them smaller and also reduces the information available to a hacker.
• Binary linking or merging: Combining multiple libraries and executables into one or more output binaries makes the application smaller and simplifies deployment scenarios.
• Opaque predicate insertion: potentially incorrect code or conditional branches are added which evaluate to known results which cannot be determined via static analysis.
• Anti-tamper: A self-protection application can be injected into the source code which helps verify if the application has been tampered with in anyway. In case tampering is detected, the app can shut itself down or even limit functionality.

​Data Encryption
All data exchanged via the app must be encrypted to ensure, even if it is stolen, the criminals cannot read it. An algorithm is used to turn text into jumbled code thus ensuring the apps security. I.e. it is a jumble of non-coherent alphabets to anyone who tries to read it without the necessary key.
For example,

• HTTP is unencrypted and verifiable communication and can be read by any hackerand even be modified.
• HTTPS guarantees a secure version of HTTP. This protocol was designed for secure communication over the internet and it is encrypted by Transport Layer Security (TLS). These cryptographic protocols ensure privacy, data integrity, validate a server’s identity, ensure messages are not modified and verify the authenticity of communication. 

Key management is crucial to ensure encryption efforts pay off. The key must be secured in a container which is not on the same device. Encryption protects sensitive data at all times and can be used to protect data on servers, databases, communication channels and emails as well.

Awareness and Precautions Against Possible Threats
There are different types of attacks which can be expected in this world of cybercrime. Some attackers hack systems, while some might use the phishing form of social engineering. In this type of attack, a hacker learns the user information, login credentials and passwords by pretending to be a reputable entity via email or other communication channels and installs malware through a link or attachment.
Man-in-the-middle or MITM attack intercepts communication between two parties and allows the attacker to eavesdrop and even manipulate the communications. For example, the communication between a mobile app and the database which stores the information can be tampered with.
Extra precaution needs to be taken when using third party libraries and the codes must be thoroughly tested before being used in the app. For example, iOS systems use closed libraries, unlike android, hence hackers find it close to impossible to get source code from iOS libraries. If a libraries source code is public, then necessary precautions would need to be taken like code obfuscation to protect the data.

Cache
The cache exists to preserve temporary data and must be emptied periodically to free up space and avoid problems due to corrupt cache data. A devices cache stored elements of apps so they can load quickly. This includes sensitive user information and login details.
Invalid and outdated information can be stored in cache causing some apps to show errors and hence it is important to clear an apps cache during the testing phase to avoid bugs. Android systems manage cache effectively and there is no longer a need to manually clear the cache.

Data Storage
A device stores its data like media files and settings files locally until the settings are manually changed by the user. For example, Whatsapp stores photos and files sent by or received by users.
Steps need to be taken to secure the stored data to prevent unauthorized access, corruption or destruction. If the data is not protected it can be easily hacked and any stored data will be vulnerable. Following steps can be taken to ensure stored data is protected:

• Locally stored data is encrypted by means of a key
• Keys are stored on the server side and not client side
• Secret keys can be stored within the app if there is no server
• Sensitive data must not be stored on devices
• Secret keys are necessary to identify that someone is an authorized user

High-Level Authentication
Authentication refers to passwords and other personal identifiers which act as a barrier to entry. As a developer it is possible to encourage users to create more case sensitive passwords for authentication. For example,

• Alphanumeric passwords
• Multi-factor authentication
• One time password (OTP)
• Biometric authentication

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Modern users are acutely aware of the threats surrounding them virtually and are rightfully concerned about the security of the apps they use. Smartphones are being used now more than ever and any breaches and access to data not correctly secured by the app can have a detrimental effect on the future of the organization.
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App owners and developers need to accept that it does not matter which platform, Android or iOS, the app is being developed for, the workload for security testing must not be taken lightly. Even an iOS platform is not completely secure and hackers will continue trying to get through its code.
All the above mentioned techniques enable a successful app development with the necessary mobile application security practices to help safeguard the app and the data within. For more details you can contact the App Scoop mobile app developers: https://www.app-scoop.com/contact-us.html