Function secret sharing(FSS)is a secret sharing technique for functions in a specific function class,mainly including distributed point function(DPF)and distributed comparison function(DCF).As an important basis for f...Function secret sharing(FSS)is a secret sharing technique for functions in a specific function class,mainly including distributed point function(DPF)and distributed comparison function(DCF).As an important basis for function secret sharing,DPF and DCF are the foundation for the extension of this technique to other more general and complex function classes.However,the function classes corresponding to the current DPF and DCF schemes are almost all unary function classes,and there is no efficient construction for multivariate function classes.The applications of FSS can be extended with the development of a multivariate scheme,e.g.,a multi-keyword private information retrieval scheme can be constructed.To solve this problem,this paper presents a binary DCF scheme based on the“two-layer binary tree”structure.In a binary tree structure,each node computes the seed of its child nodes based on its own seed.The key technique is to realize the transition transfer of seeds by using oblivious transfer,to connect two unary structures.Theoretical analysis and experimental results show that our binary scheme changes from single-round communication in the original definition to multiround communication,and has great advantages in communication cost and computation efficiency.For the security parameterλand input length n,the key size is reduced from to O(λn2)to O(λn)In addition,we explore the extensions and applications of the above method.In the batch computation,this paper uses oblivious transfer(OT)extension to realize the one-time transmission of multiple pairs of seeds and optimize its communication efficiency.By extending the structure from“two-layer”to“multi-layer”,a secret sharing scheme of multivariate mixed basic function is proposed based on the serial thought.Furthermore,by employing the parallel thought,a general 2-layer FSS structure from OT for multivariate mixed basic functions is explored to enhance the efficiency,where the first layer is composed of d parallel binary trees with d representing the input dimension,and the second layer is one binary tree of depth d.And the applications of our schemes in multi-keyword private information retrieval are presented.展开更多
A round function based on chaos is designed combining Feistel structure’s pseudo-randomness, chaotic system’s parameter sensitivity and image data characteristics. The round function composes of two parts--data tran...A round function based on chaos is designed combining Feistel structure’s pseudo-randomness, chaotic system’s parameter sensitivity and image data characteristics. The round function composes of two parts--data transformation based on Feistel(abbreviated as FST) and sampling output based on chaos(abbreviated as SMP). FST bases on Feistel structure and several efficient operations including bitwise xor, permutation and circulating shift. SMP is a chaos based pseudo-random sampling algorithm. It is from theoretical analysis that the round function is a pseudo-random function. The upper bounds of the average maximum differential probability and average maximum linear probability are p^2 and q^2 respectively. Finally, the good pseudo-randomness of the round function is examined with the NIST random test. The design of this round function provides an important cryptographic component for the design of chaotic image encryption algorithm.展开更多
当前,数据已成为关键战略资源,数据挖掘和分析技术在各行业发挥着重要作用,但也存在着数据泄露的风险。安全函数计算(Secure Function Evaluation,SFE)可以在保证数据安全的前提下完成任意函数的计算。Yao协议是一种用于实现安全函数计...当前,数据已成为关键战略资源,数据挖掘和分析技术在各行业发挥着重要作用,但也存在着数据泄露的风险。安全函数计算(Secure Function Evaluation,SFE)可以在保证数据安全的前提下完成任意函数的计算。Yao协议是一种用于实现安全函数计算的协议,该协议在混淆电路(Garbled Circuit,GC)生成和计算阶段含有大量加解密计算操作,且在不经意传输(Oblivious Transfer,OT)阶段具有较高的计算开销,难以满足复杂的现实应用需求。针对Yao协议的效率问题,基于现场可编程门阵列(Field Programmable Gate Array,FPGA)的异构计算对Yao协议进行加速,并结合提出的轻量级代理不经意传输协议,最终设计出轻量级异构安全计算加速框架。该方案中,混淆电路生成方和代理计算方都实现了CPU-FPGA异构计算架构。该架构借助CPU擅长处理控制流的优势和FPGA的并行处理优势对混淆电路生成阶段和计算阶段进行加速,提高了生成混淆电路和计算混淆电路的效率,减轻了计算压力。另外,相比于通过非对称密码算法实现的不经意传输协议,在轻量级代理不经意传输协议中,混淆电路生成方和代理计算方只需执行对称操作,代理计算方即可获取用户输入对应的生成方持有的随机数。该轻量级代理不经意传输协议减轻了用户和服务器在不经意传输阶段的计算压力。实验证明,在局域网环境下,与Yao协议的软件实现(TinyGarble框架)相比,该方案的计算效率至少提高了128倍。展开更多
隐私集合求交(Private Set Intersection,PSI)是安全多方计算领域的重要隐私保护技术,允许双方在不泄露各自数据集的前提下计算出交集。但现有隐私集合求交协议对参与方的计算能力要求较高,在参与方本地算力有限的前提下,对大规模数据...隐私集合求交(Private Set Intersection,PSI)是安全多方计算领域的重要隐私保护技术,允许双方在不泄露各自数据集的前提下计算出交集。但现有隐私集合求交协议对参与方的计算能力要求较高,在参与方本地算力有限的前提下,对大规模数据的处理效率较低。为解决上述问题,基于不经意伪随机函数和同态BFV(Brakerski/Fan-Ver-cauteren)算法构建了云辅助的可验证隐私集合求交协议。该协议在保障参与方数据安全与隐私的同时,可检测并抵抗云服务器的不当行为。在半诚实模型下证明了该协议的安全性,通过与现有协议的实验对比表明,该协议在两方数据量相差较大时效率较高,计算复杂度与通信复杂度均与集合大小呈线性相关,适用于客户端—服务端应用场景。展开更多
Existing works for securing network coding against wiretapping either incur high coding complexity or bring large bandwidth overhead. For exploiting the lightweight security mechanism for resource-constrained networks...Existing works for securing network coding against wiretapping either incur high coding complexity or bring large bandwidth overhead. For exploiting the lightweight security mechanism for resource-constrained networks, an efficient secure coding scheme is proposed in conjunction with the inherent mix- ing characteristic of network coding. The key idea is to minimize the randomizing operations to the entire plaintext data. The pro- posed scheme is shown to have properties of lightweight security complexity and lower communication overhead compared with the existing traditional solutions, and can be easy in implementation and combination with classical cryptography techniques.展开更多
基金supported by National Key R&D Program of China(No.2022ZD0161901)the National Natural Science Foundation of China(Grant No.62072023)+3 种基金Beijing Natural Science Foundation(No.4242024)the Open Project Fund of the State Key Laboratory of Cryptology,China(No.MMKFKT202120)the Exploratory Optional Project Fund of the State Key Laboratory of Complex&Critical Software Environment(No.SKLCCSE-2025ZX-XX)the Fundamental Research Funds of Beihang University,China(Nos.YWF-21-BJ-J-1041 and YWF-23-L-1033).
摘要Function secret sharing(FSS)is a secret sharing technique for functions in a specific function class,mainly including distributed point function(DPF)and distributed comparison function(DCF).As an important basis for function secret sharing,DPF and DCF are the foundation for the extension of this technique to other more general and complex function classes.However,the function classes corresponding to the current DPF and DCF schemes are almost all unary function classes,and there is no efficient construction for multivariate function classes.The applications of FSS can be extended with the development of a multivariate scheme,e.g.,a multi-keyword private information retrieval scheme can be constructed.To solve this problem,this paper presents a binary DCF scheme based on the“two-layer binary tree”structure.In a binary tree structure,each node computes the seed of its child nodes based on its own seed.The key technique is to realize the transition transfer of seeds by using oblivious transfer,to connect two unary structures.Theoretical analysis and experimental results show that our binary scheme changes from single-round communication in the original definition to multiround communication,and has great advantages in communication cost and computation efficiency.For the security parameterλand input length n,the key size is reduced from to O(λn2)to O(λn)In addition,we explore the extensions and applications of the above method.In the batch computation,this paper uses oblivious transfer(OT)extension to realize the one-time transmission of multiple pairs of seeds and optimize its communication efficiency.By extending the structure from“two-layer”to“multi-layer”,a secret sharing scheme of multivariate mixed basic function is proposed based on the serial thought.Furthermore,by employing the parallel thought,a general 2-layer FSS structure from OT for multivariate mixed basic functions is explored to enhance the efficiency,where the first layer is composed of d parallel binary trees with d representing the input dimension,and the second layer is one binary tree of depth d.And the applications of our schemes in multi-keyword private information retrieval are presented.
基金the National Natural Science Foundation of China (Grant No. 61601517)basic and advanced technology research project of Henan Province, China (Grant No. 2014302703)
摘要A round function based on chaos is designed combining Feistel structure’s pseudo-randomness, chaotic system’s parameter sensitivity and image data characteristics. The round function composes of two parts--data transformation based on Feistel(abbreviated as FST) and sampling output based on chaos(abbreviated as SMP). FST bases on Feistel structure and several efficient operations including bitwise xor, permutation and circulating shift. SMP is a chaos based pseudo-random sampling algorithm. It is from theoretical analysis that the round function is a pseudo-random function. The upper bounds of the average maximum differential probability and average maximum linear probability are p^2 and q^2 respectively. Finally, the good pseudo-randomness of the round function is examined with the NIST random test. The design of this round function provides an important cryptographic component for the design of chaotic image encryption algorithm.
摘要隐私集合求交(Private Set Intersection,PSI)是安全多方计算领域的重要隐私保护技术,允许双方在不泄露各自数据集的前提下计算出交集。但现有隐私集合求交协议对参与方的计算能力要求较高,在参与方本地算力有限的前提下,对大规模数据的处理效率较低。为解决上述问题,基于不经意伪随机函数和同态BFV(Brakerski/Fan-Ver-cauteren)算法构建了云辅助的可验证隐私集合求交协议。该协议在保障参与方数据安全与隐私的同时,可检测并抵抗云服务器的不当行为。在半诚实模型下证明了该协议的安全性,通过与现有协议的实验对比表明,该协议在两方数据量相差较大时效率较高,计算复杂度与通信复杂度均与集合大小呈线性相关,适用于客户端—服务端应用场景。
基金Supported by the National Natural Science Foundation of China(11371290,61301178)the Science and Technology Innovation Foundation of Xi'an(CXY1352WL28,CXY1352WL27)
摘要Existing works for securing network coding against wiretapping either incur high coding complexity or bring large bandwidth overhead. For exploiting the lightweight security mechanism for resource-constrained networks, an efficient secure coding scheme is proposed in conjunction with the inherent mix- ing characteristic of network coding. The key idea is to minimize the randomizing operations to the entire plaintext data. The pro- posed scheme is shown to have properties of lightweight security complexity and lower communication overhead compared with the existing traditional solutions, and can be easy in implementation and combination with classical cryptography techniques.