Research On Public Key Searchable Encryption Technology Without Secure Channel

With the increasing popularity of social networks in a globalized environment,the pro-cess of sharing data and information has become easier and faster at anytime and anywhere.Cloud computing and cloud storage services have become mainstream.Unfortunately,sen-sitive data on cloud storage is vulnerable to attack and therefore needs to be encrypted be-fore outsourcing.Searchable encryption is a way to gain effective access to large encrypted databases,even if encrypted data stored on untrusted server can guarantee security of data.In this paper,we first propose an efficient and secure public-key searchable encryption scheme under insecure channels.The scheme effectively solves the problem of ciphertext data retrieval in cloud storage under insecure channels.At the same time,under the ran-dom oracle model,it is proved that the scheme can achieve inside keyword guessing at-tack security(IND-SCF-IKGA)under insecure channel.And compared with the existing scheme,the overall efficiency of the scheme in terms of communication,computational cost and security is improved.Secondly,a public-key searchable encryption scheme based on combined-order bilinear pairing under insecure channel is proposed.The scheme provides a dual-system form searchable encryption structure to achieve cloud ciphertext data retrieval.Since the scheme uses a complex-order bilinear pair on an elliptic curve,it can implement a general method of converting a dual-system encryption scheme to a dual-system searchable encryption scheme under a insecure channel.At the same time,under the standard model of static assumption,it is proved that this scheme is resistant to choose keyword attack(IND-SCF-CKA)under insecure channel.Compared with the traditional searchable encrypted data retrieval scheme,this scheme has better performance in terms of computation time and security,not only shortens the length of trapdoor and ciphertext,but also requires only two bilinear operations.