We consider the problem of reliably broadcasting informations in a multihop network where some nodes are likely to fail. We consider the most general failure model: the Byzantine model, where the failing nodes can exhibit arbitrary malicious behavior, and may actively try to destabilize the network. We focus on totally decentralized solutions. Most existing solutions require strong network connectivity. This requirement becomes difficult to satisfy when the networks grows larger. In this paper, we review recent solutions that are tailored to sparsely connected networks. A typical example is the grid, where each node has at most four neighbors. We first present the Control Zones method, where the nodes are assumed to know the global network topology. Then, we introduce the Trigger method, which relaxes this requirement given that some performance cost is acceptable. Last, we present the Fractal method, which enables to preserve performances when the size of the network increases.