Abstract: A method for forming a blockchain allowing to ensure that any transaction emitted by a client is incorporated into the blockchain. This method involves N validator nodes of the network, including at most F faulty nodes with N > 3F , and implements a consensus mechanism tolerant of Byzantine faults. Each validator node forms a block of transactions received from the clients by selecting them according to their order of arrival and broadcasts this block to the other validator nodes. The validator node concatenates the block that it formed with a plurality of blocks received from the other nodes to form a composite block of f ? F + 1 blocks. Each validator node determines whether the composite blocks that it receives from the other validator nodes are valid, and if it receives N - F approval messages for the same composite block, validates the latter in the form of a decided composite block by adding to it a quorum certificate.