In this paper, we define a new property for ABE: homomorphic-policy. A combiner is able to (publicly) combine ciphertexts under different policies into a ciphertext under a combined policy (AND or OR). More precisely, using linear secret sharing schemes, we design Attribute-Based Key Encapsulation Mechanisms (ABKEM) with the Homomorphic-Policy property: given several encapsulations of the same keys under various policies, anyone can derive an encapsulation of the same key under any combination of the policies.
As an application, in Pay-TV, this allows to separate the content providers that can generate the encapsulations of a session key under every attributes, this key being used to encrypt the payload, and the service providers that build the decryption policies according to the subscriptions. The advantage is that the aggregation of the encapsulations by the service providers does not contain any secret information.Category / Keywords: public-key cryptography / Attribute-Based Encryption, Homomorphic-Policy, LSSS Date: received 20 Nov 2016 Contact author: duong-hieu phan at unilim fr Available format(s): PDF | BibTeX Citation Version: 20161122:104141 (All versions of this report) Short URL: ia.cr/2016/1089 Discussion forum: Show discussion | Start new discussion