## 1 Introduction  
Radio communications technology was first used in maritime rescue operations in 1899 and since then, tens of thousands of lives have been saved [1]. Organizational deficiencies in the field of saving lives at sea were brought to light by the tragedy of the Titanic on April 15/16, 1912. The special media impact of this disaster led to the appearance of the first version of the SOLAS (International Convention for the Safety of Life at Sea) in 1914 [2]. The need for interstate cooperation for the adoption of common rules in the naval field led to the adoption, at the ONU conference in Geneva in 1948, of the convention for the establishment of the Inter-Governmental Maritime Consultative Organization--IMCO, a name that was changed to IMO in 1982. One of the first tasks of the IMO was to adopt a new version of SOLAS (in 1960), which thus became the most important international treaty dealing with maritime safety [3]. The current SOLAS convention contains, in 14 chapters, standards considered minimum and mandatory for the construction and operation of ships and equipment from the point of view of maritime safety. Chapter IV--Radiocommunications--incorporates the Global Maritime Distress and Safety System (GMDSS) which addresses all passenger ships and all cargo ships with a gross tonnage of over 300 tons sailing in international waters. The equipment, standards, procedures/protocols, and communication frequencies provided herein are designed to increase the chances of rescue in the event of a maritime accident. They were developed through cooperation between the IMO and the International Telecommunication Union (ITU) [4]. Chapter V--Safety of navigation--provides provisions of an operational nature that are applicable to all ships on all types of voyage and provides for the obligation of all ship-masters to provide assistance to those in difficulty. Additionally, in this chapter there are established the obligatory navigation safety services that must be provided by the governments of the signatory states as well as their obligation to ensure that all ships are efficiently and sufficiently equipped from the point of view of maritime safety [2; 5]. A critical aspect of maritime safety is ensuring adequate radio communications in distress situations, in the conditions of an overcrowded electromagnetic spectrum and a noisy propagation environment. One proposed solution is the joint use of the communication and radar spectrum of various services [6]. Another solution signals the necessity of modernizing the current GMDSS system, by turning from analog to digital communications, and from voice to data transmissions [7]. This idea is supported by the development of several maritime safety systems, such as: AIS (Automatic Information System), DSC (Digital Selective Calling), or VDE (VHF Data Exchange) [7]. Other solutions rely on the use of artificial intelligence for increasing the quality of maritime communications [8]. However, in the era of digital communications, maritime distress transmissions still use analog communications, due to the paramount importance of ensuring an efficient communication framework in such situations--voice communications still remain critical in organizing SAR (search-and-rescue) operations. Also, another critical aspect supports preserving the use of analog systems in distress communications, and this is related to the vulnerability to cyberattacks. One of the strongest cyberattacks was NotPetya and took place in 2017. It caused a total loss of USD 10 billion, of which USD 300 million was the losses of the shipping company Maersk, which also lost most of its data. However, in a maritime cyber security survey conducted in 2020 by Safety at Sea and BIMCO Maritime Cyber Security, only 42% of respondents said their organizations had taken measures to protect ships from cyber threats. Moreover, with the onset of the COVID 19 pandemic, the number of cyberattacks increased by 400% [9].