  Attribute-Based Encryption (ABE) is a powerful cryptographic tool that allows
fine-grained access control over data. Due to its features, ABE has been
adopted in several applications, such as encrypted storage or access control
systems. Recently, researchers argued about the non acceptable performance of
ABE when implemented on mobile devices. Indeed, the non feasibility of ABE on
mobile devices would hinder the deployment of novel protocols and
services--that could instead exploit the full potential of such devices.
However, we believe the conclusion of non usability was driven by a not-very
efficient implementation.
  In this paper, we want to shine a light on this concern by studying the
feasibility of applying ABE on smartphone devices. In particular, we
implemented AndrABEn, an ABE library for Android operating system. Our library
is written in the C language and implements two main ABE schemes:
Ciphertext-Policy Attribute-Based Encryption, and Key- Policy Attribute-Based
Encryption. We also run a thorough set of experimental evaluation for AndrABEn,
and compare it with the current state-of-the-art (considering the same
experimental setting). The results confirm the possibility to effectively use
ABE on smartphone devices, requiring an acceptable amount of resources in terms
of computations and energy consumption. Since the current state-of-the-art
claims the non feasibility of ABE on mobile devices, we believe that our study
(together with the AndrABEn library that we made available online) is a key
result that will pave the way for researchers and developers to design and
implement novel protocols and applications for mobile devices.
