Due to the characteristics of wireless network transmission, smart home devices are vulnerable to malicious attacks. Malicious attackers can not only intercept the transmission data of smart home devices to grasp the user’s personal privacy information but also can eavesdrop the transmission between devices to forge the user’s legal information. These attacks have brought great security risks to people’s daily lives. In order to ensure the security of transmitted data, establishing keys for smart home devices is necessary. In this article, an adaptive physical-layer key generation scheme based on received signal strength (RSS) is proposed in Smart Homes. The scheme performs group quantization and adaptive quantization on the collected RSS measurements. The design of group quantization improves the randomness of the generated keys and makes 0 and 1 in generated keys more evenly distributed. The advantage of adaptive quantization is to design adaptive quantization intervals. The smart home devices can select the appropriate quantized reference levels according to the RSS measurements in different scenarios. In order to verify the practicability of the key generation scheme, we analyze the performance of the proposed scheme in static and dynamic scenarios. In addition, this scheme is compared with other key generation schemes from various performance indicators. The comparison results show that our scheme is better than other schemes in terms of randomness.

Ensuring the integrity of outsourced data is one of several functional requirements in cloud storage services, although designing an effective and secure public auditing scheme remains an ongoing research challenge. For example, a number of existing schemes are designed based on symmetric bilinear pairing, which are computationally expensive. While certificate-based auditing schemes can simplify certificate management and mitigate key escrow concern, such schemes are not popular in the literature. Therefore, we propose a lightweight certificate-based public/private auditing scheme based on asymmetric bilinear pairing for cloud storage. Specifically, we describe a new method of designing lightweight auditing schemes. Additionally, our proposed scheme is proven to be secure in the random oracle model. We then implement our scheme by using type D curve of the pairing-based library. The findings demonstrate that our auditing scheme significantly reduces client’s computation cost in the tag-generation (TagGen) phase, particularly in comparison to several other competing schemes. For example, when the block size is 10 KB, our on-line computation cost in the TagGen phase takes only 0.45 seconds, while it requires at least 62.83 seconds in other schemes. Furthermore, the findings show that when the number of blocks is fixed, the on-line computation cost in our TagGen phase is constant despite varying file sizes.

To secure the communications of home area networks, cryptographic keys need to be establish between smart home devices. Though many key agreement schemes have been proposed, they cannot be directly implemented. It is due to the reason that in some applications, smart home devices have no access to the online trusted third party. Moreover, in certain scenarios, the smart home devices are manufactured by different factories. As a result, it is a challenge to securely establish the communication keys using the secrets pre-loaded by different factories. A few key agreement schemes are designed without using the online trusted third party and the pre-loaded secrets. However, there are some problems in these schemes. In this paper, we improve these schemes and design a key agreement scheme for smart homes such that, the devices can automatically and securely establish the communication key. Specifically, our scheme is designed by making use of the secret mismatch problem (exists in the physical layer secret extraction schemes). We prove the security of the proposed scheme and present a prototype implementation. Additionally, we analyse the performance of our scheme and compare it with that of other related works. The comparison shows that our key agreement scheme can fix the problems in the related works, however, it introduces some extra communication consumptions.

In cloud Electronic Medical Records (EMRs), health-related private information such as genetics and diseases is contained. Thus, the secure ownership transfer protocol should protect users’ privacy. In certain scenarios, some users, including patients, doctors, medical and research institutions, may be offline. As a result, existing protocols cannot be directly employed. Motivated by these observations, in this paper we propose a secure and efficient ownership transfer for cloud EMRs auditing protocol. Specifically, our protocol allows the existence of offline users while ensuring users anonymity, it is achieved using different signature constructions. Additionally, a tracing mechanism is introduced to safeguard against malicious users. We rigorously prove the security of our protocol, comprehensively evaluate the performance of it, and compare our protocol with a few closely relevant protocols. According to the evaluations, our protocol significantly improves ownership transfer efficiency while achieving additional functionalities, including public verifiability, multi-ownership transferability, anonymity, and traceability.