Abstract: Aiming at the problem of data security storage and sharing in hybrid cloud,an efficient data security sharing scheme was proposed for hybrid cloud mode.In the scheme,an attribute-based encryption mechanism with ciphertext policy was used to encrypt data,the ciphertexts were stored on the public cloud through the private cloud;when mobile users wanted to access cloud data,anonymous key negotiation technology and the delegation mechanism of encryption and decryption were used to ensure fast access to data.The scheme was designed to ensure the secure storage of data on the public cloud,supporting fine-grained access control,and to arrange the private cloud to do most of the computing in the process of encryption and decryption,reducing the processing time for mobile cloud users to access cloud data.In this way,the time for encryption and decryption could be constant regardless of the increasing attributes in the access policy.