Privacy preserving ciphertext-policy attribute-based broadcast encryption in smart city

With the development and application of information technology, the problem of personal privacy leakage is becoming more and more serious. Most attribute-based broadcast encryption (ABBE) schemes focus on data security, while ignoring the protection of the personal privacy of users in access structure and identity. To address this problem, a privacy preserving ABBE scheme is proposed, which ensures the data confidentiality and protects personal privacy as well. In addition, the authenticity of encrypted data can be verified. It is proved that the proposed scheme achieves full security by dual system encryption.