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Comment by jfindley | Hacker News Reader

Even a very very cursory review of the code turns up giant red flags. As another comment noted it lacks tests, uses poor project structure and has private deps. Much more seriously, though, the encryption looks very very unsafe.

The encryption uses math/rand. This alone clearly shows the authors have absolutely no clue what they are doing. The encryption itself is also very unsafe - loads of obvious side channel attacks and really far too many flaws to cover here. This isn't just a few mistakes, this is a group of people who don't know enough to do this safely. Sorry, this stuff is hard and this project doesn't come close to meeting even the lowest bar.

1: https://github.com/CHURPTeam/CHURP/blob/master/src/utils/enc...

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One of the authors of the work here. This work is an early-stage research prototype. The particular encryption module is currently unused, it is actually part of the pessimistic path of the protocol that is not yet implemented. The code corresponds to the optimistic path of the protocol.

Thanks that's great to hear! Would you mind updating your readme and website to reflect that? It would be a shame if anyone were to rely on this for anything critical as-is.

Thanks for the comment. We added a disclaimer!

It's clearly research code meant as a proof-of-concept of their paper, not something to take and use in production.

If you're going to criticize it, maybe do it more respectfully, and also focus on the paper, ideas, and motivation, not the particular proof-of-concept code.

I'm decently familiar with this space and haven't read the paper yet, but the problem it's addressing is important.

A branded website that makes claims to solve the problem broadly doesn’t give the impression it’s “just a proof of concept”.

It even invites developers to “give it a try”.

The link was to www.churp.io which looks to me much more like a product than a research paper.

One of the authors helpfully clarified below, but at least to me it was extremely unclear that this was the case - had it been more obvious I'd have phrased my original comment very differently. On second inspection one of the blue links does point to "full paper" but there's still lots of words that imply that it's a viable working product, which it really isn't.

We posted at the same time. This is exactly right. It looks like it’s trying to be a marketed, accepted solution.

You are clearly missing the point.

Not even research code should use rand and if you are, you have just lost half of your credibility.

Ari Juels and Dawn Song know what they're doing.

Whether their students use rand in their demo code has zero impact on their credibility.

You are all right. These people know what they're doing, but they're also academics and are probably not the best implementers.

There are no lessons to be learned here.

Are you kidding ?

There is plenty of of lessons to be learned here

- Code involving cryptography should be written with some level of basic rigor, even at that prototype phase, otherwise you lose credibility (evidence above)

- Code involving cryptography that's in a prototype phase should not be marketed in a bubbly 'use this now' fashion

- Academics should be aware that their code is likely to be taken and used as is

I could go on all day.

EDIT: I left this out initially, then edited it in, then edited it out, but to claim that "they know what they are doing" so whatever their students do doesn't impact their credibility is so bizarre.

Surely these students are supposed to be being taught to go and become implementators or advise implementators. So maybe they should be taught to not use rand(), to have a clear and reproducible project build, to not provide prototype work marketed as usable, etc, etc. Cryptography is usually broken (bypassed) by implementation flaws, afaik, and I'm not even an expert.

I'm not taking a position on this code base or paper because I haven't looked much, just on the argument that "they know what they are doing so its fine" and "it's fine that academics can't implement, they are only working on cryptography"

Where did I say that this was fine? I think you are over reacting.

What about the paper? Is the idea good?

https://eprint.iacr.org/2019/017.pdf

I spent an hour or so looking at this paper in the Spring, and FWIW it seemed like a good approach to me then.

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