Abstract:Attribute-based encryption algorithm contains a large number of time-consuming exponential operations and bilinear pairing operations, therefore, some schemes propose to outsource encryption to the cloud server. However, these schemes do not provide the parallel computing method of outsourcing encryption on cloud servers. Besides, in these schemes, user manages too many private keys and the authorization center generates a private key for the user with excessive cost. To solve these problems, a fast encryption and sharing scheme based on the Spark big data platform is proposed. In this scheme, an encryption parallelization algorithm is designed according to the characteristics of the sharing access tree, with which, distribution of secret value of the sharing access tree and encryption at leaf node are parallelized. Then, the parallelization tasks are handed over to the Spark cluster. As a result, user client needs only one exponent operation for each leaf node. In addition to this, the private key attribute computation is also outsourced to the Spark cluster. In proposed scheme, the authorization center generates a user private key requiring only four exponential and users only need to save a key sub-item with small space.