摘要
大多数满足前后向隐私安全的动态可搜索对称加密方案需要为每个关键字维护状态表,如果将其存储在客户端则会带来额外的存储开销。此外,一些常数级客户端存储方案虽降低了客户端存储,但增加了更新和搜索时的计算开销、通信开销。针对目前客户端存储开销与通信开销、搜索计算开销不平衡的问题,文章基于层级索引结构,结合哈希密钥链,设计了具有O(1)客户端存储开销且满足前后向隐私安全和通信优化的动态可搜索对称加密方案(Communication and Client Storage Optimized DSSE,CCSO)。该方案利用哈希密钥链和全局计数器进行密钥分发,由哈希密钥链的单向性保证前向隐私安全,以惰性删除的方式保证后向安全,将所有关键字的状态信息绑定到全局计数器,以降低客户端存储开销;执行搜索时,仅需上传当前状态下的关键字搜索令牌即可完成对整个加密数据库的搜索操作。最后,对CCSO方案进行了安全性分析,并将其与SDa、CLOSE-FB、DISCO-h方案进行更新性能、服务器搜索性能和通信性能的对比实验。结果表明:(1)CCSO方案达到了前向隐私安全;(2)CCSO方案的搜索上行通信量仅为100 bits,远低于SDa方案的1 200 bits次线性级通信开销,提高了实用性;(3)CCSO方案的单次搜索计算耗时仅为10-4数量级,稳定优于CLOSE-FB、DISCO-h方案的10-2数量级计算耗时,达到次线性级搜索计算开销。综上所述,CCSO方案具有O(1)客户端存储开销,同时将搜索时的上行通信复杂度降低至常数级,计算复杂度降为次线性级,较好地解决了客户端存储开销与通信开销、搜索计算开销不平衡的问题。
Most dynamic searchable symmetric encryption(DSSE)schemes that satisfy forward and backward privacy require maintaining a state table for each keyword.Storing these state tables on the client side incurs additional storage overhead.Furthermore,while some constant client-side storage schemes reduce client-side storage,they increase the computational and communication overhead during updates and searches.Forward and backward privacy security are ensured and communication is optimized in a dynamically designed searchable symmetric encryption scheme with constant client-side storage,which is developed based on a hierarchical index structure and a hash key chain and designated as Communication and Client Storage Optimized DSSE(CCSO).The scheme utilizes a hash key chain and a global counter for key distribution:the one-way property of the hash key chain guarantees forward privacy,while backward security is achieved via lazy deletion.The state information of all keywords is bound to the global counter to reduce client-side storage overhead.During search execution,only the keyword search token under the current state needs to be uploaded to complete the search operation on the entire encrypted database.Finally,a security analysis of the CCSO scheme is conducted,and comparative experiments on update efficiency,search efficiency,and communication performance are performed between CCSO and existing schemes(SDa,CLOSE-FB,and DISCO-h).The results show that:(1)the CCSO scheme achieves forward privacy;(2)CCSO only requires 100 bits of uplink communication for searches,which is much lower than the sublinear communication overhead of 1200 bits in SDa,improving practicality;(3)The single-search computational latency of the CCSO scheme is only on the order of 10-4,which is lower than the 10-2 order computational latency of CLOSE-FB and DISCO-h,achieving sublinear search computational overhead.In summary,CCSO features O(1)client-side storage overhead while reducing the uplink communication complexity during search to a constant level and the computational complexity to a sublinear level,effectively addressing the imbalance between client-side storage overhead,communication overhead,and search computational overhead.
作者
严旭阳
马昌社
YAN Xuyang;MA Changshe(School of Computer Science,South China Normal University,Guangzhou 510631,China)
出处
《华南师范大学学报(自然科学版)》
北大核心
2025年第5期90-100,共11页
Journal of South China Normal University(Natural Science Edition)
基金
国家自然科学基金项目(61672243)。
关键词
动态可搜索对称加密
前向隐私安全
后向隐私安全
客户端存储
dynamic searchable symmetric encryption
forward privacy security
backward privacy security
client storage
