New Schemes About Wildcard Searchable Encryption And Identity-based Matchmaking Encryption

With the widespread use of cloud computing in various scenarios,it is still worth studying how to continuously improve the efficiency of data processing and ensure the authenticity of the identities of both parties involved while protecting privacy.Existing searchable encryption schemes mainly focus on exact matching patterns,which are insufficient to meet and cope with the increasing demand for fuzzy searches,especially lacking attention to wildcard searchable encryption.Meanwhile,previous matchmaking encryption schemes in identity-based settings either need to rely on random oracles or are based on non-standard q-type assumptions.In this paper,we study the searchable encryption schemes supporting fuzzy matching in public key settings and the identitybased matchmaking encryption respectively,and analyze and propose corresponding improvement schemes in terms of security,functionality and efficiency for the possible shortcomings and problems in previous work.Concretely,the following two schemes are proposed:Firstly,we propose a secure and practical wildcard-supported fuzzy searchable encryption system called SPWSE,based on the inner product functional encryption.The length of ciphertexts and secret keys in existing schemes have a linear growth relationship with the number of wildcards,which directly affects the efficiency of decryption operations.Additionally,existing schemes have many restrictions on wildcards,and require the number and position of wildcards as input.In this paper,we introduce a twodimensional inner product relation to remove all restrictions on wildcards and make our scheme support full wildcard search.The system constructed in this work removes redundant parameters and extra complex computations,ensuring its practicality and high efficiency.To resist active attacks from malicious adversaries and prevent information leakage,we enhance the security of our scheme to adaptive simulation-based security under the SXDH assumption.The corresponding security proof of our construction is implicitly established on a hash proof system.Finally,our system shows better performance than others in multiple groups of comparative experiments.Secondly,we propose the first identity-based matchmaking encryption scheme under standard assumptions in the standard model.Previous works are either in the random oracle model or based on the q-type assumptions and zero-knowledge proof systems,while ours is built directly and does not rely on other crypto tools.In this paper,we proposed a two-level identity-based encryption with anonymity and unforgeability which is based on dual pairing vector spaces.This two-level construction cleverly satisfies the same functionality of IB-ME,and its security properties meet their two security requirements.The privacy property of IB-ME relies on the anonymity of this two-level IBE,while the authenticity property corresponds to the unforgeability in the 2nd level.Finally,this scheme is proved to satisfy both privacy and authenticity by reducing to Waters’ dual system encryption methodology.