Wireless Body Area Networks (WBAN) is often envisioned as a paradigm shift from the traditional healthcare system to the modern E-Healthcare system. The patient's vitals sensed by the sensors are highly sensitive, confidential, and susceptible to various attacks from adversaries. For the WBAN being a concrete application of the healthcare system, it is paramount to ensure that the data sensed by the WBAN sensors is safe and not exposed to unauthorised entities and security threats. In light of this, strong security solutions and authentication schemes are needed for the success and large scale adoption of the WBANs. To this end, a plethora of security solutions and authentication schemes have been suggested by the researchers over the last two decades. However, the absence of a clear and cohesive study in view of security and authentication does not serve the bigger goal of providing a bird-eye view of the domain. To fulfill the objectives mentioned above, we approach in the following manner. Firstly, an extensive review of the security essentials, security threats, attackers, and attack techniques, and current existing solutions are provided with a detailed classification of security mechanisms in the WBANs. Secondly, a detailed discussion on authentication, design, and development of the authentication scheme and its classification, adversary models and security protocol verifiers is provided. Furthermore, this work outlines the applications, open research issues, recommendations for future authentication schemes and future trends for the WBANs. All in all, this survey elaborates the functionality of WBAN, its technologies, building blocks, and a much wider view of WBAN in terms of security and authentication.

无线体域网（WBAN）通常被设想为从传统医疗系统向现代电子医疗系统的转变。传感器感测到的患者生命体征高度敏感，机密，并且容易受到对手的各种攻击。对于WBAN作为医疗保健系统的具体应用而言，至关重要的是确保WBAN传感器感测到的数据是安全的，并且不会暴露于未经授权的实体和安全威胁下。鉴于此，WBAN的成功和大规模采用需要强大的安全解决方案和身份验证方案。为此，研究人员在过去的二十年中提出了许多安全解决方案和身份验证方案。然而，缺乏针对安全性和身份验证的清晰，一致的研究并不能达到提供该域鸟瞰图的更大目标。为了实现上述目标，我们采用以下方式进行处理。首先，对WBAN中的安全要素，安全威胁，攻击者和攻击技术以及当前的现有解决方案进行了广泛的审查，并对安全机制进行了详细分类。其次，详细讨论了认证方案的认证，设计和开发及其分类，对手模型和安全协议验证程序。此外，这项工作还概述了应用程序，未解决的研究问题，对未来认证方案的建议以及WBAN的未来趋势。总而言之，