A number of searchable encryption schemes have been widely proposed to solve the search problem in ciphertext domain. However, most existing searchable encryption schemes are vulnerable to keyword guessing attacks. During keyword guessing attacks, with the help of the cloud, an adversary will learn what keyword a given trapdoor is searching for, which leads to the disclosure of users’ privacy information. To address this issue, we propose SDKSE-KGA: a secure dynamic keyword searchable encryption scheme which resists keyword guessing attacks. SDKSE-KGA has constant-size indexes and trapdoors and supports functionalities such as dynamic updating of keywords and files. Formal proofs show that it is Trapdoor-IND-CKA and Index-IND-CKA secure in the standard model.