## 2 Related Work
### Contention-Free-Based MAC Protocol  
Contention-free MAC (CFM) protocol brings the network from an arbitrary state to a collision-free stable condition. A significant concern worth investigating is the distribution process of the contention-free MAC protocol. The steady state of contention-free MAC protocol transmits messages without collision. The metrics used in a stable condition include the efficiency of the node's throughput and the inverse time interval between when messages reach the network. In [20], the authors proposed an energy-conserving collision-free MAC protocol for underwater sensor networks. The proposed contention-free MAC protocol indicates reliability in the network. The authors in [21] proposed a collision-free coloring MAC protocol for underwater sensor networks (UWSN). The proposed protocol aims to achieve high throughput performance by avoiding collision at the MAC layer. The protocol is to improve energy efficiency and packet delivery fairness. These network design limitations concerning secure MAC protocol authorize cluster-based network design (CBND) of the individual sensor nodes. Furthermore, the network requires underwater vehicle (UV) investigation in the underwater wireless sensor network (UWSN) deployment. Therefore, our proposed SDAA protocol fulfills all these design limitations requirements and utilizes vehicle deployment in the UWSN. Our proposed SDAA protocol optimizes the network to be UVWSN, which uses secure data aggregation and authentication in CBND methods. Based upon this, we can reevaluate the reliability, energy efficiency, and packet drop in the network and compare it to other secure standard MAC protocols, such as SEFSC [6], SDA [7], and EEST [8]. Design Challenges of SEFSC, SDA, and EEST Protocols and Models of Secure Data Aggregation and Authentication Using UVWSN  
In this section, we highlight the design challenges of UWSN secure standard MAC protocols, including SEFSC [6], SDA [7], and EEST [8]. We also compare it with our proposed SDAA secure MAC protocol methods. SEFSC is a secure MAC underwater wireless sensor network (UWSN) MAC protocol, which has operated in hostile underwater conditions since it is deployed in that condition. Based on this, the protocol experienced more significant security challenges in the network. Therefore, the protocol network performance should depend on its collected mobile data. However, due to the channel unreliability nature of UWSN operation in hostile conditions, the protocol needed to achieve reliability of mobile data collection in CBND. In addition, the UWSN, which they investigated, was also vulnerable. Therefore, we anticipate malicious node attacker detection for mitigating channel unreliability challenges in the network. These channel unreliability challenges and hostile node encounters lead to communication overheads in the UWSN. However, SEFSC employed mobile data transmission to investigate UWSN channel operation conditions. Notably, multiple mobile sinks (MMS), which can appropriately plan mobile data routes, are needed to overcome communication overhead in the network. Our proposed SDAA protocol deployed in UVWSN employs MMS and overcomes these challenges. SDA is a synopsis diffusion approach that is a secure MAC protocol. This protocol solves the challenge of data integrity, which means the protocol needs accountability for the trustworthiness of data or reliability in the UWSN. However, the SDA protocol could not detect malicious node attackers (MNA) in the UWSN. Even though the SDA protocol network architecture deployment utilized a base station (BS), the BS was the only authentication method in the network. Consequently, the SDA protocol used the BS yet could not efficiently detect any MNA. Another design challenge with the SDA protocol was that the protocol only noticed a few MNA. This presupposes that the protocol deployment in the UWSN was on a small scale. Therefore, scalability is a concern, leading to more channel insecurity in the UWSN deployment.