Apple's operating system, iOS, combines hardware, software, and services to provide high security on its devices. iOS uses an AES 256-bit crypto engine and a random number generator (RNG) for file encryption.
In addition, the following encryption and data protection features are described in the iOS Security white paper published by Apple Inc. (2016):
- file data protection to protect the data stored in the device's memory
- multiple lengths passcodes for unlocking and getting access to other functionalities
- data protection classes to determine levels of protections for different files
- keychain data protection (implemented using the SQLite database) to securely store keys and log-in tokens
- access to passwords saved by Safari by interacting with keychain items
- keybags to store keys for users, devices, backup, escrow, and iCloud
References
Apple Inc. (2016). iOS security. https://www.apple.com/business/docs/iOS_Security_Guide.pdf