A lightweight Data Sharing Scheme with Resisting Key Abuse in Mobile Edge Computing

To achieve large-scale access control over the shared data, attribute-based encryption(ABE) is a good choice. However, in the existing ABE schemes, a data user which possessing a decryption-key can regenerate a new key since key randomization technique is introduced, which will incur key abuse without any responsibility. In addition, to decrypt the ciphertext, computational complexity of a user is linear to the size of attribute set, it is a formidable challenge for the resource-constrained users. To overcome the problem above, we proposed a lightweight data sharing scheme with Resisting Key Abuse in MEC base on CP-ABE. By using transforming key technique and unforgeability of signature, the proposed scheme can not only resist decryption-key regeneration but also offload decryption computation to MEC server in order to reduce the computation complexity of data user. For a data user, it only takes two exponential operations to decrypt the ciphertext. Security proofs show that our proposed scheme can provide data confidentiality and strong key unforgeability. Compared to several schemes, the proposed scheme is show to have more advantages in terms of computational cost and communication overhead by experiment simulation.