Typical cryptography schemes are not well suited for low complexity types of equipment, e. g. Internet of things (IoT) devices, as they may need high power or impose high computational complexity. Physical (PHY) layer security techniques such as beamforming (in multiple antennas systems) are possible alternatives to provide security for such applications. In this paper, we consider a network with multiple groups of users as receivers and a transmitter that intends to send different messages to each group. There are also some eavesdroppers (Eavs) at known locations of the environment. The goal of this paper is to find the beamforming vectors that minimize the total transmitting power while keeping the signal level above a threshold at the exact locations of the legitimate receivers (both angle and range) and keeping it less than another threshold at eavesdropping points. We use frequency diverse arrays (FDA) at the transmitter; thus, the transmitter also needs to determine the frequency that each antenna element must use for data transmission. This condition makes the problem non-convex and so we propose an approximate solution for solving this optimization problem. Simulation results show the performance of the scheme in a particular network setting.

Machine to machine (M2M) Communication, which is also known as machine type Communication (MTC), is one of the fascinating parts of mobile Communication technology and also an important practical application of the Internet of Things. The main objective of this type of Communication is handling massive heterogeneous devices with low network overheads and high security guarantees. Hence, various protocols and schemes were proposed to achieve security requirements in M2M Communication and reduce computational and Communication costs. In this paper, we propose the group-based Secure, lightweight handover authentication (GSLHA) protocol for M2M Communication in LTE and future 5G networks. The proposed protocol mutually authenticates a group of MTC devices (MTCDs) and a new eNodeB (eNB) when these simultaneously enter the coverage of the eNB with considering all the cellular network requirements. The security analysis and formal verification by using the AVISPA tool show that the proposed protocol has been able to achieve all the security goals and overcome various attacks. In addition, the comparative performance analysis of the handover authentication protocols shows that the proposed GSLHA protocol has the best computational and Communication overheads.

This study seeks to empirically explain the effect of public relations strategies in the Ports and Maritime Organization on Secure Communications. Accordingly, and considering the importance of Iran as a country with 11 ports and a wide range of commercial, military and passenger shipping, it should take appropriate measures for shipping safety; From this point of view, all elements of the organization (internal and external stakeholders) need to be involved in decision-making in a tangible and intangible way. The research method in this research is mixed. In the qualitative part, interview tools were used and experts were interviewed until the theoretical saturation was achieved. Coding was done using MAXQDA software and the dimensions of seafarers' problems, shareholder responsibility, maritime accident management, maritime crisis management, protection of interests Demand for seafaring, maritime culture, reducing seafarers 'concerns, seafaring culture and improving the quality of seafarers' education were identified, which were evaluated by public relations strategies. In a small part, the research hypotheses were evaluated using a questionnaire tool. SPSS and Linear Regression Method Hypotheses were analyzed and all research hypotheses were confirmed.

In this paper, we propose using Frobenius rings to increase the security of data Communication in medical health systems based on the Internet of Things. Frobenius rings are algebraic structures widely studied in mathematics and have found applications in cryptography and coding theory. We show how Frobenius rings can be used to create efficient encryption and decryption algorithms that can Secure Communications in IoT-based medical health systems. IoT refers to internet Communication between objects and equipment that are in our environment. These devices or objects connected to the Internet can be controlled and managed remotely using software on smartphones, tablets, computers, gadgets, smart watches, televisions, and any other object. Here, an attempt is made to create a safe bridge between the patient with simple medical measuring devices. The doctor who does not have direct access to him and can only receive the medical values measured by the patient through the Internet and give his definitive opinion about them, for example, the devices for measuring the patient's medical quantities can be simple mobile phone apps, and the doctor can be an artificial intelligence for medical measurements or a real doctor. We also present a case study with an example of medical factors such as heart rate, blood pressure, weight, blood sugar, and respiratory rate, which demonstrates the effectiveness of our proposed approach. Our results show that the use of Frobenius rings can significantly improve data Communication security in IoT-based medical health systems without compromising system performance. In conclusion, our proposed approach provides a suitable solution for securing data Communication in IoT-based medical health systems. The use of Frobenius rings can increase the confidentiality, integrity and availability of sensitive health information, thereby ensuring that patient's privacy is protected while enabling efficient management of their health data.