ABSTRACT
This chapter presents a new Identity-Revocable Cipher-Text Policy Attribute-Based Encryption (IR-CP-ABE) scheme that incorporates an ID-based revocation capability to enforce secure group communications on both coarse-grained and fine-grained levels. Cipher-Text Policy Attribute-Based Encryption provides a flexible data access control approach, where access policies are enforced based on users’ assigned attributes. Some roots of Ciphertext-Policy Attribute-Based Encryption can be traced back to the introduction of Identity-Based Encryption, which could be considered a special case of Cipher-Text Policy Attribute-Based Encryption. Identity Revocable-Cipher-Text Policy Attribute-Based Encryption can be used to revoke subgroup members defined by one or multiple attribute policy trees in order to construct access policies for all possible subgroups; moreover, IR-CP-ABE can be used to reduce attributes used by attribute policy trees; finally, IR-CP-ABE can revoke one or multiple group members.
