In order to showcase the efficiency of the proposed model, the authors conduct extensive experiments on a big dataset consisting of 35,000 ransomware versionsof 14 families, 500 versions of 10 malware, and 500 goodware apps aggregated at a different time from different data archives. The proposed solution enriches the accuracy, reduces the mistakes and misclassifications, and shortens the elapsed time versus escalating, big, lifelike, and imbalanced corpora of data. Dealing with malware that can launch several types of attacks, including ransomware and SolarWinds attacks, is an open issue. The authors in [7] propose an extensible and openly available malware analysis platform entitled Sisyfos. Sisyfos constitutes a significant step in the development of open, modular, and extensible malware platforms that support operational environments, including critical infrastructures. One important aspect that needs to be further investigated is the robustness and fault tolerance of such platforms, especially in boundary cases where samples may lead to system failures. The next article [8] of the Special Issue proposes an authentication scheme to be employed in rapidly changing variable message format(VMF)-based environments. It is based on the cryptographic hash chain-based authentication technology that includes a time-based one-time password (T-OTP). The proposed lightweight authentication scheme satisfies the demands for a rapidly changing battlefield network and any additional security requirements based on VMF standards. The proposed model could enhance the integrity of tactical message exchanges and reduce unnecessary network transactions and transmission bits for the authentication flow in VMF-based combat network radio (CNR) networks, while ensuring robustness with limited resources. In most public key infrastructure (PKI) schemes, the public keys are generated by private keys with Rivest-Shamir-Adleman (RSA) and elliptic curve cryptography (ECC). It is now anticipated that quantum computers (QC) will be able to break both RSA and ECC when the technology to manufacture enough quantum nodes becomes available. Paper [9] describes practical ways to generate keys from physical unclonable functions, for both lattice and code-based cryptography and proposes to generate the public-private key pairs by replacing the random number generators with data streams generated from addressable physical unclonable functions (PUFs) to obtain the seeds needed in the post quantum cryptographic (PQC) algorithms. Dissimilar to the key pairs computed by PQC algorithms, the seeds are relatively short, typically 256-bits long. Devices from the operational technologies (OT) side of this critical infrastructure, which were physically segregated in the past, are now more and more connected to the internet in a series of highly-distributed hierarchical network systems, forming the next generation electric power system or smart grids (SG). SGs are revolutionizing the energy supply sector and this trend is expected to rise in the near future. Unfortunately, SGs have become the target of several serious cyber attacks recently. The authors in [10] focus on such attack scenarios and propose a formal risk assessment framework that is based on threat modelling and probabilistic model checking. The assessment takes into consideration the technological aspects of the SG architecture. The Industrial Control System (ICS) is an umbrella term that refers to a group of process automation technologies, such as Supervisory Control and Data Acquisition (SCADA) systems and Distributed Control Systems (DCS), which, unfortunately, have been subject to a growing number of attacks in recent years. As they deliver vital services to critical infrastructure--such as communications, manufacturing, and energy among others--hostile intruders mounting attacks represent a serious threat to the day to day running of nation states. Both articles [11; 12] focus on detecting vulnerabilities and attacks in an ICS.