Blockchain-based traceability systems are a promising approach because they are decentralized, transparent, and tamper proof; however, if all traceability data are uploaded to a blockchain platform, it may affect the efficiency or even lead to data explosion. Additionally, it is difficult to guarantee the reliability of the original data source of massive Internet of Things (IoT) devices. Furthermore, when different enterprise nodes adopt different data storage structures, the costs that are associated with data sharing will increase. In this paper, we have proposed a trustworthy product traceability system that is based on hyperledger fabric and Electronic Product Code Information Service (EPCIS), which is not only capable of making products traceable, but it can also authenticate and authorize the IoT devices that are used for data collection. First, we adopted the on-chain and off-chain collaborative management mechanism in order to alleviate data explosion on the chain. Second, we proposed a scheme to authenticate and authorize devices based on blockchain. Third, we complied with EPCIS and Core Business Vocabulary (CBV) standards and provided the EPCIS location discovery service in order to improve the interactivity. Finally, we implemented and tested the proposed traceability system and compared it with the existing research. The proposed solution provides product information traceability, data tamper proofing, data confidentiality, and data source reliability.

In this paper, we present a novel high-throughput anti-collision algorithm for passive ultrahigh-frequency (UHF) radio-frequency identification (RFID) systems. Our algorithm utilizes signal recovery techniques of collided tag signals to both recover tag communications and obtain an accurate count of all tags in the field. Passive UHF RFID systems are used for long-range passive communications for applications including supply chain management and electronic tolling. Anti-collision algorithms are used to ensure successful RFID tag communications due to the likelihood of multiple tags being in the field and attempting to communicate simultaneously. The limited on-tag functionality necessitates the use of simple anti-collision algorithms such as a dynamic frame slotted Aloha (DFSA) algorithm. With our novel collision detection and signal recovery anti-collision algorithm, the RFID reader can retrieve multiple valid communications from each collided slot in a DFSA-based anti-collision protocol, while our algorithm allocates an optimal number of slots resulting in more collided but recoverable slots and fewer empty slots. Our algorithm achieves a nearly 100% throughput improvement with an expected throughput of 0.85 compared with an expected throughput of 0.426 for a standard DFSA algorithm. The reader receiver with the proposed algorithm is implemented in a field-programmable gate array and the whole reader system is verified using the communication tests with commercial tags. According to the synthesized results in an SMIC 0.13- $\mu \text{m}$ CMOS technology, the collision detection and signal recovery module consumes about 135k GE. Note to Practitioners—Signal recovery methods are capable of extracting information from collided signals. In this paper, we introduce and analyze a signal recovery method based on the voltage histogram of the received signal. Both the original signals and the number of collided signals are recovered. The information of tags is used by our novel algorithm to increase the system throughput in DFSA-based anti-collision algorithms. The recovered signals allow our algorithm to directly obtain the tag identifier. By determining the number of collided signals, our algorithm is able to calculate an accurate estimate of the total number of tags in the reader’s field. With signal recovery and an accurate tag count, our algorithm is able to reduce the total number of slots needed to identify all tags, thereby increasing the throughput. We present a novel frame length optimization method that increases throughout by shrinking the number of slots, thereby intentionally causing collisions and reducing the total number of empty slots. In addition, we present a hardware implementation of our novel method that is suitable for integration into RFID readers. When the signal strengths of the tags in collision in the in-phase or quadrature path are not close to each other, the performance of our method is much better than that of the traditional method in which the collision signal is treated as ineffective and ignored.

Internet of Things (IoT) technologies have a great potential to improve the safety and quality of agricultural products. By providing near continuous monitoring from planting through harvesting and to our homes, IoT technologies are able to provide farm to fork visibility with all of the resulting benefits that accrue from that visibility. Unique identification provides the foundation of these benefits with a name service enabling efficient storage and retrieval of the data associated with each identifier. In this work, we present iotNS, a simple, efficient enterprise-oriented name service designed for agricultural products. The iotNS provides five times faster response than the standard GS1 ONS system. The iotNS has been deployed across five cities to enable the efficient storage and retrieval of information about agricultural products as they are tracked from the farm to the market. The deployment has shown that the visibility provided by iotNS is a mechanism that fosters cooperation and supply chain improvements among the enterprises using the iotNS.

With the spread of distributed renewable energy, residents are shifting from being mere consumers to being energy producers and consumers. This role shift poses challenges to the electricity trading mechanism that connects distributed renewable energy sources to the grid. In this paper, a new efficient and secure blockchain-based distributed community energy trading mechanism is proposed, called CE-SDT. Our system is proved to be stable and scalable. It can also help shift loads and power peaks and reduce customer costs by 60%. As a result, our proposed blockchain-based trading mechanism, as compared to the centralized trading mechanism, is applied to microgrids formed by distributed renewable energy sources, not only obtaining greater economic benefits but also reducing the carbon footprint of residents, and furthermore, it promotes low or zero-carbon configurations of the power system, thereby achieving certain environmental benefits.

Radio frequency identification (RFID) is an important technique used for automatic identification and data capture. In recent years, low-cost RFID tags have been used in many open-loop applications beyond supply chain management, such as the tagging of the medicine, clothes, and belongings after the point of sales. At the same time, with the development of semiconductor industry, handheld terminals and mobile phones are becoming RFID-enabled. Unauthorized mobile RFID readers could be abused by the malicious hackers or curious common people. Even for authorized RFID readers, the ownership of the reader can be transferred and the owners of the authorized mobile reader may not be always reliable. The authorization and authentication of the mobile RFID readers need to take stronger security measures to address the privacy or security issues that may arise in the emerging open-loop applications. In this paper, the security demands of RFID tags in emerging open-loop applications are summarized, and two example protocols for authorization, authentication and key establishment based on symmetric cryptography are presented. The proposed protocols adopt a timed-session-based authorization scheme, and all reader-to-tag operations are authorized by a trusted third party using a newly defined class of timed sessions. The output of the tags is randomized to prevent unauthorized tracking of the RFID tags. An instance of the protocol A is implemented in 0.13-μm CMOS technology, and the functions are verified by field programmable gate array. The baseband consumes 44.0 μW under 1.08 V voltage and 1.92 MHz frequency, and it has 25,067 gate equivalents. The proposed protocols can successfully resist most security threats toward open-loop RFID systems except physical attacks. The timing and scalability of the two protocols are discussed in detail.

Food safety has drawn worldwide attention because of its enormous impact on human health and social stability. Although traceability systems based on Internet of Things (IoT) can improve the visibility of the food supply chain, the trust service is necessary to ensure the data origin and data integrity. This paper proposes a food traceability system supported by a trust service based on Domain Name System Security Extensions(DNSSEC). A DNSSEC-enabled traceability system is implemented for food safety in China. In the traceability system, the master data and event data of the products is stored in distributed databases owned and managed by the enterprises respectively in the supply chain. Enterprise oriented Internet of Things Information Service (iotIS) is an important component of the distributed traceability system. A trust service for the Internet of Things, iotTS, is proposed to guarantee the data integrity. With this service, it can be ensured that the information stored in the enterprise database is original and has never been manipulated. Lightweight public keys are distributed based on the DNSSEC in this solution. Compared with the existing solutions, the proposed solution has better scalability and credibility.