Adiantum is a

cipher In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode i ...

construction for

disk encryption Disk encryption is a technology which protects information by converting it into unreadable code that cannot be deciphered easily by unauthorized people. Disk encryption uses disk encryption software or hardware to encrypt every bit of data that g ...

, which uses the

ChaCha Cha-Cha, Cha Cha, ChaCha or Chacha may refer to: Music * Cha-cha-cha (dance), a dance of Cuban origin * Cha-cha-cha (music), a genre of Cuban music * ''Cha Cha'' (album), a 1978 album by Herman Brood & His Wild Romance * ''Cha Cha'' (soundtrack), ...

and

Advanced Encryption Standard The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant ...

(AES) ciphers, and

Poly1305 Poly1305 is a universal hash family designed by Daniel J. Bernstein for use in cryptography. As with any universal hash family, Poly1305 can be used as a one-time message authentication code to authenticate a single message using a key shared ...

cryptographic

message authentication code In cryptography, a message authentication code (MAC), sometimes known as a ''tag'', is a short piece of information used for authenticating a message. In other words, to confirm that the message came from the stated sender (its authenticity) and ...

(MAC). It was designed in 2018 by Paul Crowley and Eric Biggers at

Google Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...

specifically for low-powered mobile devices running

Android Go Android Go, officially Android (Go Edition), is a stripped-down version of the Android operating system, designed for low-end and ultra-budget smartphones (but is also used by some tablets). However, it is intended for smartphones with less tha ...

. It has been included in the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...

since version 5.0. HPolyC is an earlier variant of Adiantum, which uses a different construction for the Poly1305 hash function. Adiantum is implemented in

Android 10 Android 10 ( codenamed Android Q during development) is the tenth major release and the 17th version of the Android mobile operating system. It was first released as a developer preview on March 13, 2019, and was released publicly on Septembe ...

as an alternative cipher for device encryption, particularly on low-end devices lacking hardware-accelerated support for AES. The company stated that Adiantum ran five times faster than AES-256-XTS on

ARM Cortex-A7 The ARM Cortex-A7 MPCore is a 32-bit microprocessor core licensed by ARM Holdings implementing the ARMv7-A architecture announced in 2011. Overview It has two target applications; firstly as a smaller, simpler, and more power-efficient succes ...

CPUs. Google had previously exempted devices from mandatory device encryption if their specifications affected system performance if enabled. Due to the introduction of Adiantum, device encryption becomes mandatory on all Android devices beginning on Android 10.

References

External links

*
Android Open Source Project: Enabling Adiantum
Ciphers Computer-related introductions in 2018 Google {{security-stub