Studies On Two Certificateless Searchable Authenticated Encryption Schemes

Today,the world is in the information age,which inevitably brings about the rapid expansion of the amount of data,and the efficient storage and processing of data has become very significant.To ensure information security,data are used for transmission and storage in ciphertext form.Therefore,how to safely and efficiently retrieve over ciphertexts,especially those outsourced to third-party cloud servers,is a necessary research issue.At present,the public key searchable encryption is an important tool to solve the above problem.This cryptosystem can realize ciphertext retrieval without revealing any plaintext information of encrypted data and keywords.However,the traditional public key searchable encryption schemes have difficulty in certificate management and key escrow,and they are also threatened by keyword guessing attacks.Therefore,the certificateless searchable authenticated encryption scheme that integrates both advantages of the certificateless cryptosystem and the public key searchable authenticated encryption can solve the above problems at the same time.Although some certificateless searchable authenticated encryption schemes have been proposed,the provable security of most schemes relies on random oracle model and most schemes need to use high-cost operations such as bilinear pairing operations.In order to solve the above problems,this paper studies the certificateless searchable authenticated encryption and the details are as follows:(1)A new certificateless searchable authenticated encryption scheme is proposed,which does not require high computational cost operations,and has higher efficiency and lower communicational costs than existing similar schemes.In addition,the security of the new scheme can be proved in the standard model,which has higher realistic security than the same type of schemes whose security can only be proved in the random oracle model.(2)A new designated tester multi-receiver certificateless searchable authenticated encryption scheme is proposed.In terms of security,the new scheme can resist both inside and outside keyword guessing attacks under the enhanced security model.In addition,the security of this scheme can also be proved in the standard model,so it has stronger realistic security.In terms of performance,the new scheme has higher computational efficiency and lower communication cost than existing similar schemes based on bilinear pairing.In addition,the scheme is designed for multi-receiver application scenarios,so in a scenario with a large number of receivers,the performance advantage of the new scheme is more significant compared with existing similar schemes.