The relays in random linear network coding (RLNC) approach recode and transmit the coded packets to boost the performance against packet loss. However, this can endanger the system to pollution attacks, which can be eliminated by Homomorphic message authentication code (HMAC). Cache coding limits RLNC by coding only the decoded packets in the relays. In the other words, the relay node in cache coding first decodes the coded packets, then recodes and protects them by a MAC‐based scheme that allows the next hop to discover the pollution in the network. This study provides analytical models for cache coding and RLNC to compare their communication overhead. First, we approximate the number of transmissions in a network consisting several relays. The approximation models are for the cases of a few and large number of relays. Then, we validate our analysis using simulation results and illustrate that cache coding can eliminate the pollution attack issue of RLNC with only a slight increase in the bandwidth usage when there are no malicious nodes in the network. Moreover, we conclude that it is more beneficial to employ the cache coding approach at the presence of malicious nodes in the network.

中文翻译：

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组播中继网络中随机线性网络编码的安全开销

随机线性网络编码（RLNC）中的中继方法重新编码并发送编码后的数据包，以提高性能，防止数据包丢失。但是，这可能危害系统免受污染攻击，可以通过同态消息认证代码（HMAC）消除这种攻击。缓存编码通过仅对中继中的解码数据包进行编码来限制RLNC。换句话说，缓存编码中的中继节点首先对编码的数据包进行解码，然后通过基于MAC的方案重新编码并对其进行保护，该方案允许下一跳发现网络中的污染。这项研究为缓存编码和RLNC提供了分析模型，以比较它们的通信开销。首先，我们估算由几个中继组成的网络中的传输数量。近似模型适用于少量和大量继电器的情况。然后，我们使用仿真结果验证了我们的分析结果，并说明了当网络中没有恶意节点时，缓存编码可以消除RLNC的污染攻击问题，而带宽使用量只会略有增加。此外，我们得出结论，在网络中存在恶意节点的情况下，采用缓存编码方法会更有益。