Attribute-based encryption with keyword search(ABKS) achieves both fine-grained access control and keyword search.However,in the previous ABKS schemes,the search algorithm requires that each keyword to be identical between the target keyword set and the ciphertext keyword set,other-wise the algorithm does not output any search result,which is not conducive to use.Moreover,the previous ABKS schemes are vulnerable to what we call a peer-decryption attack,that is,the ciphertext may be eavesdropped and decrypted by an adver-sary who has sufficient authorities but no information about the ciphertext keywords.In this paper,we provide a new system in fog computing,the ciphertext-policy attribute-based encryption with dynamic keyword search (ABDKS).In ABDKS,the search algorithm requires only one keyword to be identical between the two key-word sets and outputs the corresponding correlation which re-flects the number of the same keywords in those two sets.In ad-dition,our ABDKS is resistant to peer-decryption attack,since the decryption requires not only sufficient authority but also at least one keyword of the ciphertext.Beyond that,the ABDKS shifts most computational overheads from resource constrained users to fog nodes.The security analysis shows that the ABDKS can resist Chosen-Plaintext Attack (CPA) and Chosen-Keyword Attack (CKA).