Systems and techniques are provided for a tree structure for byzantine fault tolerance. A validator computing device may receive a candidate block from a block producer. The block producer may be a second validator computing device of the distributed network. The validator computing device may determine whether or not the candidate block is valid. The validator computing device may sign an indication of whether or not the candidate block is valid to generate a signature. The validator computing device may send the signature to a third validator computing device that is a sibling node to the validator computing device. The validator computing device may receive a second signature from the third validator computing device. The validator computing device may combine the signature and the second signature to generate a combine signature if the signature and the second signature agree.