Underwater datacenters (UDCs) hold promise as next-generation data storage due to their energy efficiency and environmental sustainability benefits. While the natural cooling properties of water save power, the isolated aquatic environment and long-range sound propagation in water create unique vulnerabilities which differ from those of on-land data centers. Our research discovers the unique vulnerabilities of fault-tolerant storage devices, resource allocation software, and distributed file systems to acoustic injection attacks in UDCs. With a realistic testbed approximating UDC server operations, we empirically characterize the capabilities of acoustic injection underwater and find that an attacker can reduce fault-tolerant RAID 5 storage system throughput by 17% up to 100%. Our closed-water analyses reveal that attackers can (i) cause unresponsiveness and automatic node removal in a distributed filesystem with only 2.4 minutes of sustained acoustic injection, (ii) induce a distributed database's latency to increase by up to 92.7% to reduce system reliability, and (iii) induce load-balance managers to redirect up to 74% of resources to a target server to cause overload or force resource colocation. Furthermore, we perform open-water experiments in a lake and find that an attacker can cause controlled throughput degradation at a maximum allowable distance of 6.35 m using a commercial speaker. We also investigate and discuss the effectiveness of standard defenses against acoustic injection attacks. Finally, we formulate a novel machine learning-based detection system that reaches 0% False Positive Rate and 98.2% True Positive Rate trained on our dataset of profiled hard disk drives under 30-second FIO benchmark execution. With this work, we aim to help manufacturers proactively protect UDCs against acoustic injection attacks and ensure the security of subsea computing infrastructures.

翻译：水下数据中心凭借其能效与环境可持续性优势，有望成为下一代数据存储方案。虽然水的自然冷却特性可节省电力，但孤立的水生环境及声音在水中的长距离传播特性，使其面临与陆地数据中心截然不同的独特安全风险。本研究揭示了容错存储设备、资源分配软件及分布式文件系统在水下数据中心中易受声学注入攻击的独特脆弱性。通过搭建接近真实水下服务器运行环境的试验台，我们实证表征了水下声学注入的攻击能力，发现攻击者可令容错RAID 5存储系统吞吐量降低17%~100%。封闭水域分析表明，攻击者可通过（i）持续声学注入仅2.4分钟即可导致分布式文件系统节点无响应并触发自动移除机制，（ii）诱导分布式数据库延迟最高增加92.7%以降低系统可靠性，（iii）诱导负载均衡管理器将高达74%的资源重定向至目标服务器，从而引发过载或强制资源共置。此外，我们在湖泊开放水域实验中发现，攻击者使用商用扬声器可在6.35米最大有效距离内实现可控吞吐量降级。我们还研究并讨论了标准防御措施对抗声学注入攻击的有效性。最终，我们提出基于机器学习的新型检测系统，利用30秒FIO基准测试期间采集的硬盘特征数据集进行训练后，可实现0%假阳性率和98.2%真阳性率。通过本研究，我们旨在协助制造商主动防护水下数据中心免受声学注入攻击，保障海底计算基础设施的安全性。