Yes, that could work, though of course we might then have to prove that GitHub's records of when the repo was created/populated were correct -- I like mindcrime

Yes, that could work, though of course we might then have to prove that GitHub's records of when the repo was created/populated were correct -- I like mindcrime's suggestion (peer of yours) of combining that with a PR blitz, though. Re: a notary -- we're in the UK, and I believe email can be admissible in court, but its admissibility can be contested on what amount to common-sense grounds -- for example, I doubt we'd be able to use a record of an email from our own server to prove we'd sent a message with a given content on a given day unless we had a lot of backup evidence. Interesting point about an email notary -- perhaps we could even use a regular one and get a statement of the algorithm printed on dead trees notarised? I guess the question then has to be, do we just have to prove that we had developed the algorithm before the other person had the idea, or do we have to prove that it was already public?