Access authentication via blockchain in space information network.

Space Information Network (SIN) has significant benefits of providing communication anywhere at any time. This feature offers an innovative way for conventional wireless customers to access enhanced internet services by using SIN. However, SIN's characteristics, such as naked links and maximum signal latency, make it difficult to design efficient security and routing protocols, etc. Similarly, existing SIN authentication techniques can't satisfy all of the essentials for secure communication, such as privacy leaks or rising authentication latency. The article aims to develop a novel blockchain-based access authentication mechanism for SIN. The proposed scheme uses a blockchain application, which has offered anonymity to mobile users while considering the satellites' limited processing capacity. The proposed scheme uses a blockchain application, which offers anonymity to mobile users while considering the satellites' limited processing capacity. The SIN gains the likelihood of far greater computational capacity devices as technology evolves. Since authenticating in SIN, the technique comprises three entities: low Earth orbit, mobile user, and network control centre. The proposed mutual authentication mechanism avoids the requirement of a ground station, resulting in less latency and overhead during mobile user authentication. Finally, the new blockchain-based authentication approach is being evaluated with AVISPA, a formal security tool. The simulation and performance study results illustrate that the proposed technique delivers efficient security characteristics such as low authentication latency, minimal signal overhead and less computational cost with group authentication.

An econometric analysis of inter-fuel substitution in energy sector of Pakistan.

Hydroelectricity is playing a significant role in lowering CO2 emissions as it contributes a desirable platform to fulfill the growing energy demand while releasing fewer GHGs in comparison to other fossil fuels. Utilizing the trans-log production model, this study is an endeavor to investigate the potential inter-fuel substitution by estimating the substitution elasticity between pairs of coal, natural gas, petroleum, and hydroelectricity to suggest policy for Pakistan to achieve higher economic growth, environmental sustainability, and increased energy access by its citizens. Over the period 1980-2013, the ridge regression was approved to estimate the model's parameters. The findings show that the output elasticity of hydroelectricity is the highest and all the factor inputs are substitutes; whereas, the elasticity of substitution between coal vs. natural gas is the highest, thus suggesting an increased focus on the coal extraction to switch from the alternative usage of gas. Moreover, encouragement of energy subsidy programs, coupled with taxes and infrastructural developments, can be adapted to redirect technology towards hydroelectricity. Hence, the result that hydroelectricity is substituted for all fuels submit that Pakistan has the potential to switch from petroleum to cleaner energy; therefore, reducing the adverse environmental implications and to retain the ability to fuel its energy sector.