A secure hash message authentication code to avoid certificate revocation list checking is proposed for vehicular ad hoc networks (VANETs). The group signature scheme is widely used in VANETs for secure communication, the existing systems based on group signature scheme provides verification delay in certificate revocation list checking. In order to overcome this delay this paper uses a Hash message authentication code (HMAC). It is used to avoid time consuming CRL checking and it also ensures the integrity of messages. The Hash message authentication code and digital signature algorithm are used to make it more secure . In this scheme the group private keys are distributed by the roadside units (RSUs) and it also manages the vehicles in a localized manner. Finally, cooperative message authentication is used among entities, in which each vehicle only needs to verify a small number of messages, thus greatly alleviating the authentication burden. The security and performance analysis show that our scheme is more efficient in terms of authentication speed, while keeping conditional privacy in VANETs.

Urbanization presents complex challenges and opportunities for sustainable energy management. Smart grids, characterized by their advanced information and communication technologies, emerge as a pivotal solution for urban energy systems, promising enhanced sustainability, reliability, and efficiency. This paper explores the integration of smart grids within the fabric of smart cities, focusing on their role in energy management, efficiency, and the incorporation of renewable energy sources. It delves into the operational intricacies of smart grids, including demand response, consumer participation, and the balance of energy supply and demand. The challenges of cybersecurity, privacy, interoperability, and the need for robust governance and policy frameworks are also examined. Through a comprehensive review and analysis, this paper underscores the transformative potential of smart grids in urban environments and the necessity of strategic planning and policy support to realize their full benefits for sustainable urban energy futures

This paper examines about a type of skin malignant growth which is melanoma. There are numerous types of skin malignancy, for example, Basal Cell Carcinoma (BCC), Squamous Cell Carcinoma (SCC) and Melanoma. In which the deadliest type of skin disease is the Melanoma. Demise pace of melanoma has expanded among skin malignant growth patients and it is hazardous. The death rate is highest among among middle aged and elderly individuals. It is seen as risky when it develops beyond the dermis of the skin. This paper deals with a survey on a few computerized analysis procedures for diagnosing melanoma. These procedures extract different parameters, for example, shape, size, surface, shading and different properties of lesions which is utilized for additional exploration. The precise skin affected region which is the skin lesion or area of intrigue will be taken out for automated medical procedure. The ATLAS dataset or PH2 dataset pictures are considered for investigation in the majority of the papers.

In this paper two existing algorithms named as Cross-Diamond Search algorithm CDS and Fast Objected- Base Efficient Three Step Search algorithm are used. The cross-diamond search algorithm employs two diamond search patterns (a large and small) and a halfway-stop technique. It finds small motion vectors with fewer search points than the DS algorithm while maintaining similar or even better search quality. The efficient Three Step Search (E3SS) algorithm requires less computation and performs better in terms of PSNR. Modified objected block-base vector search algorithm (MOBS) fully utilizes the correlations existing in motion vectors to reduce the computations. Fast Objected- Base Efficient (FOBE) Three Step Search algorithm combines E3SS and MOBS. By combining these two existing algorithms CDS and MOBS, a new algorithm is proposed with reduced computational complexity without degradation in quality.