Aggregation of message authentication codes (MACs) is a proven and efficient method to preserve valuable bandwidth in resource-constrained environments: Instead of appending a long authentication tag to each message, the integrity protection of multiple messages is aggregated into a single tag. However, while such aggregation saves bandwidth, a single lost message typically means that authentication information for multiple messages cannot be verified anymore. With the significant increase of bandwidth-constrained lossy communication, as applications shift towards wireless channels, it thus becomes paramount to study the impact of packet loss on the diverse MAC aggregation schemes proposed over the past 15 years to assess when and how to aggregate message authentication. Therefore, we empirically study all relevant MAC aggregation schemes in the context of lossy channels, investigating achievable goodput improvements, the resulting verification delays, processing overhead, and resilience to denial-of-service attacks. Our analysis shows the importance of carefully choosing and configuring MAC aggregation, as selecting and correctly parameterizing the right scheme can, e.g., improve goodput by 39% to 444%, depending on the scenario. However, since no aggregation scheme performs best in all scenarios, we provide guidelines for network operators to select optimal schemes and parameterizations suiting specific network settings.

翻译：消息认证码（MAC）的聚合是一种经过验证的高效方法，可在资源受限环境中节省宝贵带宽：该方法并非为每条消息附加长认证标签，而是将多条消息的完整性保护聚合成单个标签。然而，尽管这种聚合能节省带宽，但通常单条消息的丢失会导致多条消息的认证信息无法再被验证。随着带宽受限的损毁通信显著增加，以及应用向无线信道迁移，研究数据包丢失对过去15年提出的各种MAC聚合方案的影响变得至关重要，以评估何时以及如何聚合消息认证。因此，我们针对损毁信道环境，对现有所有相关MAC聚合方案进行实证研究，探究其可实现的有效吞吐量提升、验证延迟、处理开销以及对拒绝服务攻击的鲁棒性。分析表明，谨慎选择和配置MAC聚合至关重要：例如，根据不同场景，正确选择并参数化合适的方案可将有效吞吐量提升39%至444%。然而，由于没有任何聚合方案在所有场景中表现最优，我们为网络运营商提供了选择适合特定网络环境的最优方案及参数化的指导原则。