# Digital Communication Forensics in 6G and beyond Networks
## 2 Literature Review
### Digital Forensics for Mobile Devices in 5G and Modern Networks  
In order to store data in connected blocks in the form of a decentralized database, blockchain technology requires a peer-to-peer network. Decentralization is a core property of blockchain technologies that well meet the needs of evidence integrity and provenance in DF across jurisdictional borders. Existing DF are confronted with new issues with regard to cyber-physical systems, such as data that are difficult to access, data that have multiple sources, transparent and traceable evidences, and the forensic analysis of huge numbers of datasets [23].  
Global usage of mobile smart devices has skyrocketed during the past ten years. As these gadgets' processing speeds and storage capacities have grown, so too has their attraction. Mobile smart devices are often utilized and incorporated into the networks of most enterprises, including phallets, smartphones, personal digital assistants, and tablets. Furthermore, huge amounts of private, commercial, and personal data are stored on these devices. They are now a target for fraudsters as a result. It was found that they were engaged in cybercrime [24].  
There is a lot of interest throughout the world in the future 5G heterogeneous networks (HetNets). Large volumes of high-velocity data may be transferred using the HetNets bandwidth spectrum, with considerable advantages but a number of drawbacks. If key visual information, such as videos and photographs, is fraudulently targeted and posted to the Internet, it may spread quickly and, as a result, severe harm to the community might happen [25].  
In the coming years, the development of 5G cellular and Internet of Things (IoT) technologies will be widely deployed. In addition, investigators are expected to handle a variety of cyber and internet difficulties in their investigations as crime rates rise. IoT devices can, therefore. be utilized to expedite the investigative process, particularly when it comes to identifying suspects. Few studies have examined the effectiveness of face sketch synthesis (FSS) models based on deep learning across a variety of application areas, including traditional face recognition [26].  
Despite its potential involvement in a wide range of cyber-attacks, IoT bot malware is still relatively young and there is little forensic knowledge of it. Consider, for example, the distributed denial of service (DDoS) assault that prevented millions of Internet users from accessing more than 1200 websites, including social media, in 2016. This attack lasted for practically the whole day. IoT botnet forensics are essential due to an increasing number of an estimated 50 billion IoT devices and their expanding interconnectivity to traditional networks and even to one another with the deployment of 5G networks. Mirai botnet has had a widespread and considerable effect due to the weak defenses and access protections found in many IoT devices. The 2016 public release of its source code1 resulted in numerous Mirai variants and an increase in the frequency of DDoS attacks [27].  
In a BYOD context driven by IoT [28], the authors examine the ecosystem for cyber forensics as well as security problems. They performed a simulation in three stages to find trends in the traffic that was being targeted. In the first stage, BYOD users from outside the company were tested utilizing mobile devices linked to the corporate network without VPN services. The second stage entailed inserting BYOD customers using untrusted personal devices into the company's corporate wireless network and monitoring harmful activity. In the third phase, a model of the typical BYOD environment process was constructed, and a systematic procedure for BYOD secured ecosystem development modes was established. They discovered that in order to safeguard corporate networks against unreliable BYOD devices, a whole ecosystem of harmful traffic detection and management is required. The recommendation for a cyber forensics BYOD secure infrastructure requires advanced level security as its conclusion.