Although current Blockchain systems like Bitcoin or Ethereum clearly represent breakthrough technologies for realizing financial services without the need of central trust, they suffer with a basic problem to realize a wide range of financial services: They focus on instant payments and money sending. Most financial products however are not build on the instant payment but rather on a promise of a future payment. In this sense instead of the basic services, like a certain M amount of money, Bitcoin or Ether is transferred, the basic protocol should focus somehow on the fact that a certain amount of M money will be transferred in a future t time point. As a consequence atomic transactions should be rather build up with the help of <M,t> tuples. Certainly it is a very good question if the Blockchain can help somehow that the certain amount of M money is really or with a high probability will be really transferred at the t time point.
