I have a new cipher, and I want to get it properly vetted, but I don't have a strong way to prove its security properties. I'm an amateur without ties to a strong cryptographer/university. I have attempted a few indistinguishability proofs, but these are "back of the napkin" proofs and are likely not rigorous. (I have colleagues that have done cryptanalysis on it, but they are not theorem types.)

As a result, I feel that I don't stand a chance of getting it published without a proof of security, but I feel that I can't find someone to help without it being published.

How can I find someone willing to join on and help write a compelling proof, and generally help write a compelling paper, (or identify a weakness that prevents me from doing something stupid with the cipher)?

Given that I have done these things:

* Review previous ciphers, find they're not what you want, invent new cipher
* Internally analyze it (plots, prototype code, etc.)
* Socialize it to cryptanalyst peers, get tentative green light (rather, absence of red light - no new findings in a while)

Is this a reasonable path going forward:

* [Brief it at an IACR](https://www.iacr.org/events/) rump session
* Have follow-on discussions at conference, express my need, find someone that way
* Submit as a work-in-progress in lower tier, but bonafide crypto conference
* Submit as a journal article

Is a rump session a good way to go to find interested math types, and/or as a first step to announcing the idea? Are there other alternatives, such as quarterly meetings of some group that might be willing to hear the idea?

Similarly, is there a good "starter conference" for crypto open to new ideas that might lack the mathematical rigor?

[In contrast to this thread, How to publish a cipher (concept)](http://crypto.stackexchange.com/questions/33274/how-to-publish-a-cipher-concept/33292#33292), the main answer suggests that formalisms are a prerequisite to publishing: "If you submit a cipher, one would expect at least a formal analysis of why you think this is a good idea." My question is what if you don't have that ability - how do you find someone that can help with that? The rest of the answers on the thread went into how to make it into a bachelor's thesis. 

In additional defense of this thread, there are many great suggestions that don't appear on that other post. While I'm biased - but have nothing to gain - these threads are unique. I'm okay with marking as duplicate as long as somehow you can merge the useful answers below into the other question.