A lot of companies in all kinds of sectors (finance, healthcare, etc) are looking into blockchain (or DLT) because it allows for a database model that is not ce

A lot of companies in all kinds of sectors (finance, healthcare, etc) are looking into blockchain (or DLT) because it allows for a database model that is not centralised. This is great in situations where you don't fully trust other parties you are doing business with. A lot of these companies are doing experiments using private blockchains (like the private ethereum network linked in OP). However depending on how much you trust the "other" parties allowed to mine (or sign blocks), you might still have the risk where one or more conspire against you and 51% attack you. Periodically putting a blockheader of your private chain into a public blockchain would be a great solution to this, as pulling off a 51% attack on bitcoin is rather hard.