Efficient revocable attribute-based encryption scheme

In the existing solutions,the time-based scheme is difficult to achieve immediate revocation,and the third-party-based scheme often requires re-encryption,which needs large amount of calculation and doesn’t apply to mas-sive data.To solve the problem,an efficient and immediate CP-ABE scheme was proposed to support user and attribute lev-els revocation.The scheme was based on the classic LSSS access structure,introducing RSA key management mechanism and attribute authentication.By means of a semi-trusted third party,the user could be authenticated before decryption.Com-pared with the existing revocation schemes,The proposed scheme didn’t need the user to update the key or re-encrypt the ciphertext.The semi-trusted third party wasn’t required to update the RSA attribute authentication key.The scheme greatly reduced the amount of computation and traffic caused by revocation,while ensuring anti-collusion attacks and forward and backward security.Finally,the security analysis and experimental simulation show that the scheme has higher revocation ef-ficiency.     

属性可撤销且密文长度恒定的属性基加密方案

密文策略属性基加密（ciphertext-policy attribute-based encryption,CP-ABE）类似于基于角色访问控制,可以为云存储系统提供灵活细粒度的访问控制.但大多数CP-ABE方案中,密文长度与访问策略复杂度成正相关,系统属性同时被多个用户共享而导致属性难以被撤销.针对上述问题,本文提出一种支持属性撤销且密文长度恒定的属性基加密方案.该方案中每个用户的属性群密钥不能通用,可以有效抵抗撤销用户与未撤销用户的合谋攻击.为减少属性授权机构和数据拥有者的计算负担,属性撤销过程所需的计算量外包给数据服务管理者;同时该方案采用支持多值属性和通配符的"AND"门策略,实现了密文长度恒定.所提方案基于决策性q-BDHE（q-bilinear Diffie-Hellman exponent）假设对方案进行了选择明文攻击的安全性证明.最后对方案进行了理论分析与实验验证,分析结果表明本文方案可以有效抵制用户合谋攻击,增加了方案的安全性.同时所提方案在功能和计算效率方面具有一定优势,适用于实际应用情况.     

MACPABE: Multi-Authority-based CP-ABE with efficient attribute revocation for IoT-enabled healthcare infrastructure

The Internet of Things (IoT) technology along with cloud computing has gained much attention in recent years for its potential to upgrade conventional healthcare systems. Outsourcing healthcare data to a cloud environment from IoT devices is very essential as IoT devices are lightweight. To maintain confidentiality and to achieve fine-grained access control, the ciphertext policy attribute-based encryption (CP-ABE) technique is utilized very often in an IoT-based healthcare system for encrypting patients' healthcare data. However, an attribute revocation may affect the other users with the same attribute set, as well as the entire system due to its security concerns. This paper proposes a novel CP-ABE-based fine-grained access control scheme to solve the attribute revocation problem. The proposed technique includes multiple attribute authorities to reduce the work overhead of having a single authority in the traditional CP-ABE systems. In addition, the proposed scheme outsources the decryption process to a decryption assistant entity to reduce the decryption overhead of the end-users. To prove the efficiency of the proposed scheme, both formal security analysis and performance comparisons are presented in this paper. Results and discussion prove the effectiveness of the proposed scheme over some well-known schemes.     

Efficient revocable certificateless remote anonymous authentication protocol for wireless body area network

To ensure the security and privacy of patients’ health data in wireless body area network (WBAN),communication parties must be mutual authenticated.Now some bilinear pairings led to a larger computation cost for users and tree structure revocation would lead to larger user storage cost.In order to achieve revocation and reduce the cost of the user side,a novel revocable certificate less remote anonymous authentication protocol for WBAN was proposed by using elliptic curve cryptography and revoke algorithm that could revoke users by updating their time-private-keys.Security requirements including anonymity,mutual authentication and session key establishment were satisfied in proposed scheme.Compared with the existing schemes,the experimental analysis shows that the computation cost and storage cost of the authentication protocol are greatly reduced,which is more suitable for resource-constrained WBAN.Security analysis also shows that the protocol is secure in the random oracle model.     

Attribute-Based Access Control with Efficient and Secure Attribute Revocation for Cloud Data Sharing Service

Nowadays, there is the tendency to outsource data to cloud storage servers for data sharing purposes. In fact, this makes access control for the outsourced data a challenging issue. Ciphertext-policy attribute-based encryption (CP-ABE) is a promising cryptographic solution for this challenge. It gives the data owner (DO) direct control on access policy and enforces the access policy cryptographically. However, the practical application of CP-ABE in the data sharing service also has its own inherent challenge with regard to attribute revocation. To address this challenge, we proposed an attribute-revocable CP-ABE scheme by taking advantages of the over-encryption mechanism and CP-ABE scheme and by considering the semi-trusted cloud service provider (CSP) that participates in decryption processes to issue decryption tokens for authorized users. We further presented the security and performance analysis in order to assess the effectiveness of the scheme. As compared with the existing attribute-revocable CP-ABE schemes, our attribute-revocable scheme is reasonably efficient and more secure to enable attribute-based access control over the outsourced data in the cloud data sharing service.     

Secure personal data sharing in cloud computing using attribute-based broadcast encryption

The ciphertext-policy (CP) attribute-based encryption (ABE) (CP-ABE) emergings as a promising technology for allowing users to conveniently access data in cloud computing. Unfortunately, it suffers from several drawbacks such as decryption overhead, user revocation and privacy preserving. The authors proposed a new efficient and privacy-preserving attribute-based broadcast encryption (BE) (ABBE) named EP-ABBE, that can reduce the decryption computation overhead by partial decryption, and protect user privacy by obfuscating access policy of ciphertext and user's attributes. Based on EP-ABBE, a secure and flexible personal data sharing scheme in cloud computing was presented, in which the data owner can enjoy the flexibly of encrypting personal data using a specified access policy together with an implicit user index set. With the proposed scheme, efficient user revocation is achieved by dropping revoked user's index from the user index set, which is with very low computation cost. Moreover, the privacy of user can well be protected in the scheme. The security and performance analysis show that the scheme is secure, efficient and privacy-preserving.     

SecCloudSharing: Secure data sharing in public cloud using ciphertext‐policy attribute‐based proxy re‐encryption with revocation

An efficient cryptography mechanism should enforce an access control policy over the encrypted data to provide flexible, fine‐grained, and secure data access control for secure sharing of data in cloud storage. To make a secure cloud data sharing solution, we propose a ciphertext‐policy attribute‐based proxy re‐encryption scheme. In the proposed scheme, we design an efficient fine‐grained revocation mechanism, which enables not only efficient attribute‐level revocation but also efficient policy‐level revocation to achieve backward secrecy and forward secrecy. Moreover, we use a multiauthority key attribute center in the key generation phase to overcome the single‐point performance bottleneck problem and the key escrow problem. By formal security analysis, we illustrate that our proposed scheme achieves confidentiality, secure key distribution, multiple collusions resistance, and policy‐ or attribute‐revocation security. By comprehensive performance and implementation analysis, we illustrate that our proposed scheme improves the practical efficiency of storage, computation cost, and communication cost compared to the other related schemes.     

Fine-grained data access control for distributed sensor networks

Distributed sensor networks are becoming a robust solution that allows users to directly access data generated by individual sensors. In many practical scenarios, fine-grained access control is a pivotal security requirement to enhance usability and protect sensitive sensor information from unauthorized access. Recently, there have been proposed many schemes to adapt public key cryptosystems into sensor systems consisting of high-end sensor nodes in order to enforce security policy efficiently. However, the drawback of these approaches is that the complexity of computation increases linear to the expressiveness of the access policy. Key-policy attribute-based encryption is a promising cryptographic solution to enforce fine-grained access policies on the sensor data. However, the problem of applying it to distributed sensor networks introduces several challenges with regard to the attribute and user revocation. In this paper, we propose an access control scheme using KP-ABE with efficient attribute and user revocation capability for distributed sensor networks that are composed of high-end sensor devices. They can be achieved by the proxy encryption mechanism which takes advantage of attribute-based encryption and selective group key distribution. The analysis results indicate that the proposed scheme achieves efficient user access control while requiring the same computation overhead at each sensor as the previous schemes.     

数据外包环境下一种支持撤销的属性基加密方案

In order to support fine-grained attribute revocation in data outsourcing systems,an attribute-based encryption scheme with efficient revocation in indirect revocation model was proposed.The model of ABE supporting attribute revocation was given,and a concrete scheme was constructed which proved its security under the standard model.Compared to the existing related schemes,the size of ciphertext and private/secret key is reduced,and the new scheme achieves fine-grained and immediate attribute revocation which is more suitable for the practical applications.     

On the Security of “Secure and Lightweight Authentication with Key Agreement for Smart Wearable Systems”

Over the years, the performance of devices used to gather sensitive medical information about individuals has increased substantially. These include implanted devices in the body, placed on or around the body, creating a Wireless body area network. Security and privacy have been a greater concern over a period of time due to the sensitive nature of the data collected and transmitted by the network. It has been noticed that various techniques have been applied to secure the data and provide privacy in WBANs but with a tradeoff of execution overhead. Although the latest available anonymous authentication schemes provide privacy and security but due to the limited computation capacity of WBAN devices, these schemes show greater time cost for authentication and consume more processing time. We review two latest anonymous authentication schemes for the WBAN environment in terms of computation cost. These two schemes provide anonymous authentication and use encryption to secure the data and ensure privacy. Then we analyze a recent lightweight authentication scheme proposed for wearable devices which provides anonymity and privacy along with security with very low computation cost. This scheme uses hash functions in order to obtain authentication and anonymity and doesn’t use encryption in the authentication process. This scheme is not proposed for the WBAN environment, but it can be applied on the WBAN environment with necessary variations. The comparison of these available schemes shows clearly that the computation cost is considerably decreased by applying the latest authentication scheme in the WBAN environment. We propose a new authentication scheme for the WBAN environment based on the light-weight scheme proposed for wearable devices. The detailed analysis shows that our proposed scheme minimizes the computation cost and maintains the privacy and security along with anonymous authentication.

     

云存储环境下的密文安全共享机制

With the convenient of storing and sharing data in cloud storage environment,the concerns about data security arised as well.To achieve data security on untrusted servers,user usually stored the encrypted data on the cloud storage environment.How to build a cipertext-based access control scheme became a pot issue.For the access control problems of ciphertext in cloud storage environment,a CP-ABE based data sharing scheme was proposed.Novel key generation and distribution strategies were proposed to reduce the reliance on a trusted third party.Personal information was added in decryption key to resistant conclusion attacks at the same time.Moreover,key revocation scheme was proposed to provide the data backward secrecy.The security and implement analysis proves that proposed scheme is suit for the real application environment.     

支持直接撤销的密文策略属性基加密方案

提出一种支持直接撤销的属性基加密方案,首先给出支持直接撤销的属性基加密定义和安全模型,其次给出具体的支持撤销的密文策略——属性基加密方案并对安全性进行证明,最后,与其他方案对比显示,该方案在密文和密钥长度方面都有所减少。该方案可以实现对用户进行即时撤销,当且仅当用户所拥有的属性满足密文的访问结构且不在用户撤销列表内时,才能使用自己的私钥解密出明文。     

前向安全的密文策略基于属性加密方案

为降低密文策略基于属性加密（ABE, ciphertext-policyattribute-based encryption）体制中私钥泄漏带来的损害,首先给出了前向安全CP-ABE体制的形式化定义和安全模型,然后构造了一个前向安全的CP-ABE方案。基于判定性l-BDHE假设,给出了所提方案在标准模型下的安全性证明。从效率和安全性2个方面讨论了所提方案的性能,表明所提方案在增强CP-ABE体制安全性的同时,并没有过多地增加计算开销和存储开销,更适合在实际中应用。     

TF‐CPABE: An efficient and secure data communication with policy updating in wireless body area networks

The major challenge in wireless body area networks (WBAN) is setting up a protected communication between data consumers and a body area network controller while meeting the security and privacy requirements. This paper proposes efficient and secure data communication in WBANs using a Twofish symmetric algorithm and ciphertext‐policy attribute‐based encryption with constant size ciphertext; in addition, the proposed scheme incorporates policy updating to update access policies. To the best of the author's knowledge, policy updating in WBAN has not been studied in earlier works. The proposed scheme is evaluated in terms of message size, energy consumption, and computation cost, and the results are compared with those of existing schemes. The result shows that the proposed method can achieve higher efficiency than conventional methods.     

Multi-keyword search over encrypted data with user revocation

A mu1ti-keyword search over encrypted data was proposec1 with fi1e-1eve1 access authorization and data user revocation scheme through emp1oying ciphertext-po1icy attribute-based encryption（CP-ABE）.The scheme supports fi1e-1eve1 access authorization in the mu1ti-owner mu1ti-user settings，which means that data users cou1d on1y gain the authorized fi1es encrypted by different data owners with different keys.Moreover，the scheme cou1d achieve data user revocation.Forma1 security ana1ysis shows that the proposed scheme cou1d resist the chosen keyword attack in random orac1e.Moreover，the experimenta1 study over rea1-wor1d dataset demonstrates its efficiency and feasibi1ity in practice.     

云存储环境下无密钥托管可撤销属性基加密方案研究

属性基加密因其细粒度访问控制在云存储中得到广泛应用。但原始属性基加密方案存在密钥托管和属性撤销问题。为解决上述问题,该文提出一种密文策略的属性基加密方案。该方案中属性权威与中央控制通过安全两方计算技术构建无密钥托管密钥分发协议解决密钥托管问题。通过更新属性版本密钥的方式达到属性级用户撤销,同时通过中央控制可以实现系统级用户撤销。为减少用户解密过程的计算负担,将解密运算过程中复杂对运算外包给云服务商,提高解密效率。该文基于q-Parallel BDHE假设在随机预言机模型下对方案进行了选择访问结构明文攻击的安全性证明。最后从理论和实验两方面对所提方案的效率与功能性进行了分析。实验结果表明所提方案无密钥托管问题,且具有较高系统效率。     

支持属性撤销的适应性安全属性基加密方案

Attribute revocation is inevitable and also important for Attribute-Based Encryption (ABE) in practice. However, little attention has been paid to this issue, and it remains one of the main obstacles for the application of ABE. Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the user's private keys will be affected when the revocation events occur. Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the user's private keys will be affected by revocation, they mostly focused on the user revocation that revokes the user's whole attributes, or they can only be proven to be selectively secure. In this paper, we first define a model of adaptively secure ABE supporting the attribute revocation under direct revocation model. Then we propose a Key-Policy ABE (KP-ABE) scheme and a Ciphertext-Policy ABE (CP-ABE) scheme on composite order bilinear groups. Finally, we prove our schemes to be adaptively secure by employing the methodology of dual system encryption.     

雾计算中细粒度属性更新的外包计算访问控制方案

针对基于密文策略的属性加密(CP-ABE)在低时延需求较高的雾计算环境中,存在加解密开销大、属性更新效率低的问题,提出了一种雾计算中细粒度属性更新的外包计算访问控制方案,使用模加法一致性秘密(密钥)分享技术构建访问控制树,将加解密计算操作外包给雾节点,降低用户加解密开销;结合重加密机制,在雾节点建立组密钥二叉树对密文进行重加密,实现对用户属性的灵活更新。安全性分析表明,所提方案在决策双线性Diffie-Hellman假设下是安全的。仿真实验结果表明,所提方案中用户加解密时间开销相比其他方案更小,属性更新效率更高。     

面向云存储的基于属性加密的多授权中心访问控制方案

已有基于属性加密的访问控制研究多是基于单授权中心来实现,该种方案在授权方不可信或遭受恶意攻击的情况下可能会造成密钥泄露。提出一种基于属性加密的多授权中心访问控制模型PRM-CSAC。基于CP-ABE方法,设计多授权中心的属性加密方案以提高密钥安全性;设计最小化属性分组算法,使用户访问文件时,能够按需分配密钥,减少不必要的属性密钥分配,降低重加密属性数量,提高系统效率;增加读写属性加强加密方对文件的访问控制,使访问控制策略更加完善。安全性分析及仿真实验表明,相比已有方案,PRM-CSAC对用户访问请求的响应时间更短,开销较小,且能够提供很高的安全性。     

体域网中一种基于无线信道特征的密钥生成方法研究

无线体域网是以人体为中心的无线网络,受其有限的资源和计算能力的约束,如何保证无线体域网通信节点间共享密钥是当前面临的一大挑战。提出了一种基于超宽带无线体域网信道特征的密钥生成机制,利用超宽带信道多径相对时延与平均时延的差值量化生成密钥,降低了密钥不匹配率,同时引入辅助节点,提高了密钥生成速率。仿真结果表明,该机制能够在兼顾密钥一致性的前提下,获得较高的密钥生成速率并保证密钥的安全性。