Attribute-based Broadcast Encryption Scheme For LightWeight Devices

Time: 14:30 to  16:00 Ngày 19/01/2018

Venue/Location: B4-705, VIASM

Speaker: Trịnh Viết Cường


In the context of Attribute-based Encryption (ABE), a user is able to decrypt the ciphertext as long as she possesses sufficient attributes to decrypt. However,  in many practical scenarios, we expect that some specific users in the system should be revoked even when they possess sufficient attributes to decrypt. To deal with this problem, the notion of Attribute-based Broadcast Encryption (ABBE) has been introduced by Lubicz and Sirvent.  ABBE combine the funtionalities of Broadcast Encryption and Attribute-based Encryption in an efficient way. In the relevant applications such as mobile pay-TV, satellite transmission or internet of things, the users are given a relatively small device with very limited secure memory in a smartcard. Therefore, it is of high interest to construct schemes with compact secret key of users. Even though extensively studied in the recent years, it is still an open question of constructing an ABE or an ABBE with constant-size private keys for general forms of access policy such as CNF or DNF forms.

In this talk, we first give an introduction of ABBE in general, and then we present our work on ABBE (joint work with Sebastien Canard and Duong-Hieu Phan, published at IET Information Journal 21 August 2017) which can solve the aforementioned open question. More precisely, in our work we propose the first constant size private key ciphertext-policy attribute-based broadcast encryption scheme for DNF form.