Selective Data Dissemination using Attribute Based Encryption
Eun‐Kyu Lee, Ki Young Lee · Advanced science and technology letters · 2015
Ciphertext-Policy Attribute-Based Encryption provides an encrypted access control mechanism for broadcasting messages. A secret message is encrypted with an access control policy tree that contains the logical combination of different attributes. Each qualified user can apply and obtain a private key, which is associated with the various attributes of the applicant. Only the users whose attributes satisfy the policy tree can decrypt the message. However, in some scenarios, dynamic attributes are required and hence new keys must be regenerated and issued whenever a dynamic attribute updates, even if there might be hundreds of attributes involved in the key. This is not efficient since the cost of generating new private key is proportional to the number of attributes associated with that private key. In this paper we introduce the concept of Dynamic Attribute Based Encryption, a key revocation mechanism, which is necessary to prevent a user from keeping a private key with expired attributes.