A Review of Key Delegation Schemes in Ciphertext Policy-Attribute Based Encryption
Shardha Porwal, Sangeeta Mittal · 2023
Secret keys are the cornerstone of any encrypted communication. In multicast cryptosystems like Attribute based Encryption (ABE), secret keys are assigned to users as per their attributes. Delegation of rights is a useful feature in collaborative environments and thus needs to be developed for ABE based systems also. In this work, we define the distinguishing key delegation features in existing Ciphertext Policy based ABE schemes. Specifically, the controlled delegation and key abuse aspects have been analyzed. Popular existing schemes have been evaluated with respect to these aspects as well as security models considered. In the process, some gaps were identified in existing key delegation approaches and are presented in this work.