Research On Searchable Encryption Scheme Based On Unrecognized Trapdoors In Cloud Environment

As a new storage mode,cloud storage can not only help users solve physical storage overhead,but also allocate it on demand,providing users with larger and better storage services at any time.However,after the data is stored in the cloud,the security of the data is completely out of the physical control of the user,so it is an effective method to encrypt the data in advance and upload it to the cloud storage.Aiming at the keyword security problem and server credibility problem in searchable encryption,using bilinear computing method and blockchain technology to research trapdoor and malicious server environment,the main research contents include:Attribute-based encryption has been widely used in ciphertext retrieval in the cloud environment,but the flexible control of attributes and the privacy of key trapdoors are still difficult problems to be solved in ciphertext retrieval.Aiming at the flexibility of access policy,this paper proposes a denial of access strategy and uses the mutual matching algorithm of data sets to implement bidirectional attribute control in the cloud server.In the privacy leakage problem of the trapdoor,the random number is used to ensure the trapdoor unrecognizable,so that the trapdoor can effectively resist the cloud server and the external attacker's guessing attack on the keyword.The security analysis of the scheme can be implemented to the BDBH difficult problem.At the same time,the theoretical analysis and experimental analysis of the scheme are carried out.After repeated experiments on the real data set,the results show that the scheme has higher security and retrieval.effectiveness.Aiming at the trapdoor security problem of the public key encryption scheme,a random number constructing trapdoor and index is introduced to defend against keyword guessing attacks from the server and avoid data leakage caused by server curious behavior.Research on trusted issues of third parties,combine the blockchain mechanism with a searchable encryption scheme,and use smart contracts as trusted third parties for retrieval,which can prevent keyword guessing attacks inside the server and ensure retrieval.The correctness of the results,thereby limiting the malicious behavior of the server when sending data.The solution is analyzed for security and the verification scheme satisfies IND-KGA security.Experiments in real data sets,compared with other programs,prove that the program has certain advantages in time overhead.