Blockchain has gained a lot of attention in non-financial applications like the Internet of Things (IoT). It is characterized by security, decentralization, anonymity, and auditability. Today's technology makes extensive use of the internet of things to gather data from sensors and carry out specific tasks by processing it according to the requirements. To produce secure and impermeable records of transactions, the collected data can be transferred through the blockchain network. The integration of blockchain with IoT has enormous promise due to its ability to offer decentralized computing, storage, and exchange for IoT data. Conventional blockchains generally have low throughput, long transaction delays, and rely on computationally expensive consensus algorithms. However, because of its limitations, IoT applications need a blockchain network that has a lightweight consensus algorithm to integrate with it successfully. In this paper, we implement and design a Lightweight Practical Byzantine Fault Tolerance (LPBFT) consensus algorithm that improves the conventional (PBFT) algorithm. Through the implementation of the proposed LPBFT, it has shown: a simpler message structure; doesn't need a primary server; low computation time; and consists of just two stages (request and reply). That makes it workable efficiently in IoT networks.

Suspension systems are one of the main parts of the vehicle that provide the passenger comfort and stability, while it is difficult for conventional passive suspension systems to cope with the vibrations to which the vehicle is exposed. Air suspension systems have a dynamic character that allows good handling of the road and a comfortable ride, but in a certain area for this reason the stiffness of the air suspension must be flexibly changed. The air suspension has been developed with the inclusion of a hydraulic actuator to create an additional force that withstands the incoming vibration from the road. The pneumatic suspension system parameters, such as vertical acceleration, road holding, and vertical displacement, are improved continuously based on the controllers that have been used for nonlinear pneumatic suspension systems, fractional order proportional integral derivative (FOPID), and fuzzy logic control (FLC). The genetic algorithm is utilized to tune the controller's parameters to the nonlinear active pneumatic system's 3-DOF. A model's simulation outcomes with controllers improved the suspension performance. The proposed active pneumatic system and pneumatic suspension systems are compared when a vehicle is traveling at a speed of 72 km/h on an ISO level B road to test the ability and efficiency of the system to suppress body vibration to enhance safety and provide a comfortable ride on rough roads. According to simulation results, the improved suspension substantially lowers vertical vibrations and enhances road adaptability.

Multilevel Security (MLS) is one of the ways that protects the stored information in the computer and mobile devices. It classifies users and information into levels of security; thus, the user can access information within its level or less.A smartphone is used in managing some of businesses, controlling the home and car devices within the smart city environment by using a set of data stored in the database. The database is used by more than one authorized user some of this data is confidential and important that requires protection from un authorized users.In this research a proposed system to implement the MLS principle within three levels of security is presented. The first level gives the user its own security level. The second level transfers users through the system parts according to their security level (system administrator or regular user). The third level allows users to manipulate the stored encrypted data in SQLite database by using a simple and quick cryptographic algorithm.The proposed system is implemented in the smart mobile devices which are supported by the Android operating system. The experimental result showed that the proposed system has the ability to protect the data in the database and prevents users to view the data at upper levels. Also, the inability of users to change the security level of data that prevents the leak of data from the upper security levels to the lower level. Moreover, the proposed system works quickly and needs a little storage space.