String Encryption

String encryption is an essential obfuscation technique to hinder reverse engineering and static analysis of iOS applications. Plaintext strings, such as backend URLs, API keys, internal identifiers, error messages and configuration parameters, often serve as starting points for understanding the application's internal logic and for identifying sensitive targets by attackers.

In the iOS context, this information can be extracted from the Mach-O binary via static analysis tools or simple commands, allowing improper inspection of strategic data even without running the application.

Technical Mechanism: MAD applies string encryption directly to the application's compiled binary, ensuring that sensitive text literals are not available in readable form. Protected strings are decrypted only at runtime, strictly at the moment they are needed for the application's operation. This approach significantly reduces the exposure of critical information during static analysis of the binary, making automated extraction of sensitive data more difficult and limiting the effectiveness of common reverse engineering tools.