Selective IoT Access with Scalable CP-ABE Revocation and Delegation

With the evolution and advancement of IoT devices, privacy and security of data have become a critical concern. Ciphertext Policy Attribute Based Encryption (CPABE) is a selective access control scheme that provides finegrained confidentiality and privacy of data. Proxy-based Immediate Revocation of Attribute Based Encryption (PIRATTE), a variant of CP-ABE scheme provides revocation without the need of re-encrypting and issuing new keys to the nonrevoked users which CP-ABE fails to address. Scalable Proxybased Immediate Revocation (SPIRC) scheme overcomes the limitations of PIRATTE as it does not require maintaining a prior revocation list, re-encryption and re-distribution of keys. We present an extension of SPIRC that supports scalable user and attribute revocation along with delegation. Attribute revocation allows the system to revoke specific attributes of a user instead of revoking the user entirely. In our construction, each attribute of a user registering with a trusted server is associated with constant random parameters. These set of parameters associated with each attribute of a user are independent of the ciphertext. If server modifies the parameters associated with the user's decryption key, decryption by the user will not be permitted. Performance analysis of SPIRC with attribute revocation and its comparison with PIRATTE scheme is demonstrated.