How to Implement Data-at-Rest Encryption in Android Apps Using AI

What Is Data at Rest Encryption?

Data encryption is the process of converting readable data (plaintext) into an unreadable format (ciphertext), ensuring that even if the data is intercepted, it remains protected and inaccessible without the appropriate decryption key. Common encryption techniques, including AES and RSA, are designed to protect sensitive data, such as login credentials and payment information. Data encryption is also essential for complying with regulations, such as the Payment Card Industry Data Security Standard (PCI DSS), which mandates strong encryption practices to protect financial transactions and user data.

In mobile applications, data exists in three distinct states:
Data at rest: Information stored persistently on the device, such as files saved in the app’s sandbox or installation directory.
Data in transit: Information transmitted between the app and external servers or between users.
Data in use (also referred to as in-memory data): Information temporarily stored in the app’s memory during processing, which may originate from or be destined for storage or transmission.

Appdome’s TOTALData™ Encryption feature is specifically designed to protect data at rest and data in use within mobile apps, ensuring sensitive data is encrypted whether it is stored persistently or processed in memory before being saved or transmitted. TOTALData™ Encryption is simple to implement and does not affect the app’s behavior or performance. Unlike DIY methods, which require developers to manually choose and integrate encryption libraries, cipher configurations, and key management solutions, we handle everything automatically.
You can choose to protect just data at rest, just data in use, or combine both with any other feature in Appdome’s Mobile Security Suite—all without writing a single line of code.

How Appdome Protects Mobile Apps With Data at Rest Encryption?

Data at Rest Encryption is an integral part of Appdome’s TOTALData™ Encryption. Data at Rest secures all data generated by the app at runtime using AES-CTR 256-bit encryption, a widely trusted standard for protecting sensitive information. This approach allows fast, partial access to files, especially useful when reading a buffer or mapping a section into memory, without the need to decrypt the entire file. It’s more efficient than AES-CBC, which is commonly used by third-party SDKs and encryption libraries, and requires processing the whole file. We apply encryption dynamically, with no dependence on the app’s file structure, database format, or the way that the data is organized.

Appdome uses symmetric encryption to protect app data, with encryption keys generated dynamically at runtime. With AES algorithms, keys are never stored on the device. Instead, they are derived in real time each time the app runs. We can also strengthen this process by factoring in contextual data—such as the app’s bundle ID (a unique app identifier), the device ID, file checksums (used to verify data integrity), user input (like passwords or tokens), and the app’s runtime conditions, such as whether a debugger is present.

You can exclude specific files or folders from encryption, or choose to exclude all media files or all web files. For advanced use cases, Appdome also supports integration with an external Key Management System (KMS), giving customers more control over how encryption keys are derived.

Post-Quantum Cryptography

Post-Quantum Cryptography (PQC) is a cryptographic algorithm designed to defend against the potential threats posed by quantum computers. Many security systems today rely on asymmetric data encryption. This technique is still considered safe, since breaking it requires solving complex mathematical problems that are computationally infeasible for regular computers. Quantum computers pose a new challenge to traditional encryption, as they can solve asymmetric encryption problems (such as factoring large numbers) exponentially faster than classical computers.
Appdome provides strong PQC defenses against this emerging threat. For Data at Rest encryption, Appdome uses AES-256-CTR, a type of symmetric encryption, which is generally more resistant to quantum attacks. Even with Grover’s algorithm—a quantum technique that effectively reduces key strength by half—AES-256 remains highly secure and is considered quantum-resistant for the foreseeable future.