Summary In big cities, the drivers face a major problem in identifying an optimal vacant parking space for their vehicles as the number of vehicles has rapidly grown over the recent years. This objective of determining the available parking space results in wastage of time, air pollution, and traffic congestion. Smart parking systems facilitate the driver to book parking slots and attain real‐time parking information. However, the existing smart parking solutions necessitate the disclosure of sensitive information like desired destination from the vehicle drivers. Moreover, the current smart parking solutions are highly centralized, making them vulnerable for launching privacy breaches by service providers and resulting in the issues of single‐point failure. In this paper, ring signature and improved multi‐transaction mode consortium blockchain‐based private information retrieval (RS‐IMTMCB‐PIR) scheme is proposed for privacy preserving in smart parking system. This RS‐IMTMCB‐PIR scheme initially utilizes an improved multi‐transaction mode consortium blockchain constructed by different number of parking lot owners in order to achieve maximized parking offers based on the factor of availability, transparency, and security. It incorporates an improved private information retrieval approach for protecting the location privacy of drivers and secretly retrieving the offers of parking from the improved multi‐transaction mode consortium blockchain. It further utilizes the benefits of ring signature for permitting the drivers in a potential anonymous authentication process that aids in available parking slot reservation. The simulation results of this proposed RS‐IMTMCB‐PIR scheme portrayed a predominant performance in ensuring maximized degree of drivers' privacy with reduced computation and communication overheads.

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PurposeMandibular third molar (M3) extraction is the common surgical procedures carried out; however, one of the complications is development of periodontal disease in adjacent second molars (M2). Hence the purpose of this study was to evaluate the effect of extraction of M3 on the periodontal status of M2. Materials and MethodsStudy included 120 sites with mandibular M2 adjacent to the impacted M3. Plaque index(PI), gingival index(GI), probing pocket depths(PD), clinical attachment levels(CAL), Gingival recession(GR) and alveolar bone height(ABH) before and 9-12 months after surgical extraction of M3 were assessed. Patients perception was assessed using dichotomous rating. Four types of impactions(IMP) were included along with surgical cofactors like degree of impaction, flap design, bone removal, tooth sectioning. ResultsAt baseline mesioangular and horizontal IMP showed greater PPD and CAL. After extraction of M3 there was significant decrease in PPD & CAL. 14% cases showed significant increase gingival recession at the distobuccal of M2. Although 10.9% of patients had an alveolar bony defect(ABD) distal to the M2, there was considerable improvement in ABH from baseline. The ABDs are mostly associated with mesioangular and horizontal IMP. ConclusionExtraction of impacted M3 proves to be beneficial on periodontal status of M2. However, occasionally, mesioangular and horizontal IMP are likely to develop ABD distal to M2 and hence can be followed by regenerative procedures to prevent the formation of ABD.

The paper gives an insight on cryptography within digital money used in electronic commerce. The combination of digital currencies with cryptography is named as cryptocurrencies or cryptocoins. Though this technique came into existence years ago, it is bound to have a great future due to its flexibility and very less or nil transaction costs. The concept of cryptocurrency is not new in digital world and is already gaining subtle importance in electronic commerce market. This technology can bring down various risks that may have occurred in usage of physical currencies. The transaction of cryptocurrencies are protected with strong cryptographic hash functions that ensure the safe sending and receiving of assets within the transaction chain or blockchain in a Peer-to-Peer network. The paper discusses the merits and demerits of this technology with a wide range of applications that use cryptocurrency.