Fig. 4From: An efficient MAC-based scheme against pollution attacks in XOR network coding-enabled WBANs for remote patient monitoring systemsThe source node has to calculate and append 4 MACs to the end of the native packet M i , which consists of eight codewords (i.e., m i ,…,m 8). To generate the 4 MACs, a pseudo-random function is used firstly to generate four random values (i.e. r 1,…,r 4), one for each MAC. Based on these random values, the source node defines the indexes of the codewords, which will be the input to the hash function h in order to calculate the corresponding hash values h(1),…,h(4)Back to article page