Earlier quoted context omitted.
That is different use case. How would I prove that a file existed without a middlemen? I would gladly switch since the method I am currently using isn't exactly cheap.
> How would I prove that a file existed without a middlemen? How are you defining "middleman"? You can do this with any basic commitment scheme: take a cryptographically secure hash of your file and publish it somewhere that's either (1) trivially copyable, or (2) difficult to tamper with. Alternatively, you could do an online scheme where someone asks you for your proof and you present them with your hash after bein…
A simple example of what I need without a middlemen.
A student writes a thesis. The last time he is allowed to modify the file is friday evening. He can now send the file via mail or deliver in person to prove that the thesis was finished by then. However he then trusts either the mail server administration or the person at the front desk. This is fine in most cases and works like this since decades. I however do not want to trust a person or company. I do not want ANY possible explanation how I could have archived it in a different way.