Device security is something that’s been talked about for years now, where handset makers are incorporating a variety of security tools to help protect the contents on your phone from prying eyes. However some of these security features aren’t available on all devices and this is largely due to some devices using lower-end hardware.
This is something that Google is hoping to address which is why the company has since announced Adiantum. The name itself might not necessarily mean anything to you, but it is essentially Google’s way of bringing file encryption to lower-end Android devices. As Google notes, most new Android devices support AES encryption as they run on the ARMv8 platform.
Since Android devices are so varied, there are some older and lower-end Android devices that use ARMv7 processors, and as such do not come with hardware support for AES encryption. This is because these processors are too slow where if AES were to be implemented, it would result in a poor user experience. Adiantum is said to solve that problem as this new encryption mode claims to be 5 times faster compared to AES on chips that do not support hardware acceleration. According to Google:
“To solve this problem, we have designed a new encryption mode called Adiantum. Adiantum allows us to use the ChaCha stream cipher in a length-preserving mode, by adapting ideas from AES-based proposals for length-preserving encryption such as HCTR and HCH. On ARM Cortex-A7, Adiantum encryption and decryption on 4096-byte sectors is about 10.6 cycles per byte, around 5x faster than AES-256-XTS.”
That being said, Adiantum will require devices to run on Android Pie, and it will also be up to the discretion of Android manufacturers to enable the feature, so whether your device will support it is really up to the manufacturer.