This document proposes a scheme that uses ElGamal signature in network coding to enhance security. Network coding allows nodes to generate output packets as linear combinations of input packets. However, this makes the network vulnerable to pollution attacks where malicious nodes can insert corrupted packets. The proposed scheme signs data packets with ElGamal signatures. When nodes receive packets, they can verify the signatures' validity to check for corrupted packets without decoding. The scheme exploits the linearity of network coding and allows nodes to easily check packet integrity. An example is provided to demonstrate how the ElGamal signature scheme would work in the context of network coding for content distribution.