Google has developed a new storage encryption solution that will boost encryption capabilities for low-end Android devices that don’t have the hardware to support AES.
Researchers said the new solution, called Adiantum, allows the use of 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,” according to a Feb. 7 blog post.
“The ChaCha20 stream cipher is much faster than AES when hardware acceleration is unavailable, while also being extremely secure,” the post continues. “It is fast because it exclusively relies on operations that all CPUs natively support: additions, rotations and XORs.”
Currently, Android offers storage encryption using AES, but on many devices it is so slow that it would result in a poor user experience; apps would take much longer to launch, and the device would generally feel much slower.
Android device manufactures can enable the feature for either full-disk or file-based encryption on devices with AES performance greater than or equal to 50 MiB/sec, and launching with Android Pie, the blog said.