Skip to main content
Software Engineering

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

Required fields*

12
  • 13
    How does this help? Anyone who can decrypt cipher can just republish the same way with their own secret key and you have no way of proving which party published first and which copied from the other without trusting some third-party record of publication time. Commented Dec 15, 2014 at 18:04
  • 2
    @R.. Content on the internet usually has a date associated with it (e.g.: forum posts). If there are multiple people claiming to be the original inventors/ discoverers, then you just check the dates. Commented Dec 15, 2014 at 18:26
  • 2
    You can also include some content in the plaintext that is encrypted via P(content). The true owner of S will be able to decrypt that additional information, whereas a reposter will not be able to do that. Commented Dec 15, 2014 at 19:30
  • 10
    @Paul: But then the encryption is irrelevant. It's equivalent to just posting your plaintext content and relying on the date. Commented Dec 15, 2014 at 20:16
  • 2
    @R.. the idea is that, without knowing S, it is very hard to come up with a piece of text cipher2 such that P(cipher2) isn't gibberish. With S it is trivial, as S("the text you want") = cipher2. Doing the reverse amounts to defeating the crypto method. Commented Dec 16, 2014 at 2:07