Notarising legal transactions of any kind is the basic work of a notary. The legal effect of a purchase contract only becomes effective through notarial certification. The aim of blockchain is to make the manipulation of transactions or the falsification of data impossible. This technology could be a substitute for the notary. Each entry, which is normally made in the land register, would be deposited in a block chain network. Here the data would remain permanently and cannot be changed. Thus, this network could be given the legal status that the land register has. The expensive fees for the notary public would then be obsolete. Especially for smaller investments this prospect is very interesting. There are already providers who offer the depositing of documents in the block chain. These can be used to guarantee the authenticity of documents. In the future all participants of the network would know that this transaction has taken place and was legitimate. Legitimacy via the block chain also costs a small fee, but these are ridiculously low compared to notary fees.