Wireless Machine to Machine （M2M） communications enable ubiquitous sensing, controlling, and acting via sensors, actuators, and actors. Reliability and security are of foremost importance in wireless M2M systems. A simple, target distinguishing attack can result in M2M＇s failure. This paper presents a Reliable and SEcure scheme, RISE, which is a package of policies that guarantee the reliability of data （including sensor reports and actuator instructions） and devices （including sensors, actuators, and actors）. The data reliability is improved by four algorithms, ChooseMedian, ChooseMost, ChooseNearest, and Trust-based Enhancement. Report attainability is improved via m repeat-sending and n multiple-reporting algorithms. Device reliability is guaranteed by device-indistinguishability, which comprises data-indistinguishability and behavior-indistinguishability. The security requirements are formally defined, and the security analysis proves the soundness and completeness of the scheme,
Smart grid is envisioned as a critical application of cyber-physical systems and of the internet of things. In the smart grid, smart meters equipped with wireless sensors can upload meter readings （data） to smart grid control and schedule centers via the advanced metering infrastructure to improve power delivery efficiency. However, data gathered in short intervals, such as 15 minutes, will expose customers＇ detailed daily activities （for example, when they get up and when they use oven） using nonintrusive appliance load monitoring. Thus, data must be hidden to protect customers＇ privacy. However, data accountability is still required for emergency responses or to trace back suspected intrusions, even though the data is anonymous. In addition to desired security requirements, this imposes two extra tasks： Sensors in smart meters usually have resource constraints; thus, the desired security protocols have to remain lightweight in terms of computation and storage cost. Furthermore, scalability and flexibility are required since there exist vast meters. This paper presents a lightweight Privacy-aware yet Accountable Secure Scheme called PASS which guarantees privacy-aware accountability yet tackles the above challenges in the smart grid. A formal secu- rity analysis justifies that PASS can attain the security goals, while a performance analysis verifies that PASS requires few computations, and is scalable and flexible.
Utilizing OnLine Short Text （OLST） in social networking tools such as microblogs, instant messag- ing platforms, and short message service via smart phones has become a routine in daily life. OLST is ap- pealing for personal covert communication because it can hide information in a very short carrier text, and this concealment is hard to detect due to the diversity of normal traffic. However, designing appropriate schemes confronts several challenges： they need to be provably secure, and their performance needs to maintain high efficiency and handy usability due to the short length of OLST messages. In this paper, we propose a family of customized schemes known as HiMix, HiCod, HiOpt, and HiPhs for text steganography in OLST. These schemes are evaluated in terms of their security and their performance with regard to two metrics that address the particular characteristics of OLST： hiding rate and hiding ease. All proposed schemes are proved to be at least computationally secure, and their performance in terms of hiding rate and hiding ease justifies their applicability in social networking tools that utilize OLST.
Mobile Cloud Computing usually consists of front-end users who possess mobile devices and back-end cloud servers. This paradigm empowers users to pervasively access a large volume of storage resources with portable devices in a distributed and cooperative manner. During the period between uploading and downloading files （data）, the privacy and integrity of files need to be guaranteed. To this end, a family of schemes are proposed for different situations. All schemes are lightweight in terms of computational overhead, resilient to storage compromise on mobile devices, and do not assume that trusted cloud servers are present. Corresponding algorithms are proposed in detail for guiding off-the-shelf implementation. The evaluation of security and performance is also extensively analyzed, justifying the applicability of the proposed schemes.
Network coding can improve network efficiency by extending copy-and-forward paradigm to code-and- forward paradigm. It thus imposes a security problem called pollution attack that some network coding or forwarding nodes may intentionally fabricate, modify, forge, or drop packets. Recently, many authentication methods are proposed to guarantee the correctness of encoding and forwarding results via the verification from receivers. Those methods include homomorphic hashing, homomorphic message authentication code, and homomorphic signature. However, those schemes result in expensive computation overhead due to the homomorphic cryptographic primitives, so that those methods will not be able to work in most applications that confront resource constraints. In this paper, we propose an ultra-lightweight checking protocol to guarantee the secure network coding without any homomorphic cryptographic primitives. The extensive analysis proofs that it has following advantages： the least security assumption for intermediate nodes, the least cryptographic primitive requirement, ultra-lightweight computation, flexible message length with probably proof, and minimal rounds in terms of message exchanging.
