Fundamenta Informaticae - Volume 157, issue 1-2

Authors: Chen, Yuling | Lei, Min | Ren, Wei | Ren, Yi | Qu, Zhiguo

Article Type: Research Article

Abstract: Cloud computing paradigm is becoming very popular these days. However, it does not include wireless sensors and mobile phones which are needed to enable new emerging applications such as remote home medical monitoring. Therefore, a combined Cloud-Internet of Things (IoT) paradigm provides scalable on-demand data storage and resilient computation power at the cloud side as well as anytime, anywhere health data monitoring at the IoT side. As both the privacy of personal medical data and flexible data access should be provided,attackers exploit diverse social engineering and technology attacks ways, access to personal privacy information stored in the home medical monitoring …cloud, with more and more social engineering attacks.Therefore, the data in the Cloud are always encrypted and access control must be operated upon encrypted data together with being fine-grained to support diverse accessibility. Since a plain combination of encryption before access control is not robust and flexible, we propose a scheme referred to as RoFa, with tailored design. The scheme is introduced in a step-by-step manner. The basic scheme (BaS) makes use of cipher-policy attributes based encryption to empower robustness and flexibility. We further propose an advanced scheme (AdS) to improve the computation efficiency by taking the advantages of proxy-reencryption. AdS can greatly decrease the computation overhead on hospital servers due to operation migration. We finally propose an enhanced scheme (EnS) to protect integrity by using aggregate signature. RoFa describes a general framework to solve the secure requirements, and leaves the flexibility of concrete constructions intentionally. We finally compare the robustness and the flexibility of the proposed schemes by performance analysis. Show more

Keywords: Access Control, Cloud Computing, Internet of Things, Fine Grained, Robust and Flexible Security

DOI: 10.3233/FI-2018-1624

Citation: Fundamenta Informaticae, vol. 157, no. 1-2, pp. 167-184, 2018

Authors: Zhang, Jindan | Wang, Baocang

Article Type: Research Article

Abstract: Recently how to audit cloud storage correctly and securely is a very hot research topic for cloud storage. At Infocom 2015, Chen et al. proposed a novel secure cloud storage audit protocol based on distributed string equality checking, which is a very interesting result. In this paper, we give some improvements to their protocol to strengthen its security. In particular, we show that if the data owners reuse pseudorandom function on the same order number of file block when uploading file block’s tag to the cloud, the protocol maybe not secure any more. We also show that there can exist …many (mi , ci ) pairs which will result in the same inner product sum ∑ i = 1 n m i ⋅ c i , while mi denotes the file block, ci denotes the challenge value, and n denotes the number of blocks. We emphasis here that the flaw maybe does not lie in the traditional security model of cloud storage auditing protocol, but we think it is actually a serious drawback for current secure cloud storage audit protocols. We emphasis these two flaws can also exist in some famous cloud auditing protocols such as PDP and POR. Finally, we give an improvement to their protocol, and thus also give a way to strengthen the famous PDP and POR protocols. Show more

Keywords: Cloud storage auditing, security analysis, inner product

DOI: 10.3233/FI-2018-1625

Citation: Fundamenta Informaticae, vol. 157, no. 1-2, pp. 185-199, 2018

Authors: Wei, Fushan | Zhang, Ruijie | Ma, Chuangui

Article Type: Research Article

Abstract: Two-factor authenticated key exchange (TFAKE) protocols are critical tools for ensuring identity authentication and secure data transmission for cloud computing. Until now, numerous TFAKE protocols based on smart cards and passwords are proposed under this circumstance. Unfortunately, most of them are found insecure against various attacks. Researchers focus on cryptanalysis of these protocols and then fixing the loopholes. Little attention has been paid to design rationales and formal security models of these protocols. In this paper, we summarize the security requirements and put forward a formal security model for TFAKE protocols for cloud computing. We then present an efficient TFAKE …protocol without using expensive asymmetric cryptology mechanisms to achieve high efficiency. Our protocol can be proven secure in the random oracle model and achieves user anonymity. Compared with other TFAKE protocols, our protocol is more efficient and enjoys provable security. Show more

Keywords: two-factor authenticated key exchange, password, smart card, provable security, cloud computing

DOI: 10.3233/FI-2018-1626

Citation: Fundamenta Informaticae, vol. 157, no. 1-2, pp. 201-220, 2018