Comment by tptacek | Hacker News Reader

Comment by tptacek | Hacker News Reader

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I like that! From now on, when you want to introduce some new crypto idea, just make sure not to call it a "product", then issue a $1000 contest to assure people the idea works. Why doesn't everyone do that?

Oh, wait, I think Schneier answered that:

Contests are a terrible way to demonstrate security. A product/system/protocol/algorithm that has survived a contest unbroken is not obviously more trustworthy than one that has not been the subject of a contest. The best products/systems/protocols/algorithms available today have not been the subjects of any contests, and probably never will be. Contests generally don't produce useful data. There are three basic reasons why this is so.

They are:

1. The contests are generally unfair.

2. The analysis is not controlled.

3. Contest prizes are rarely good incentives.

I'd submit that (1) doesn't count here, because the idea you're demonstrating is so obviously flawed that contestants aren't at any disadvantage. But (2) and (3) are absolutely valid here: there's no structure to the contest (it's a bunch of Hacker News people poking at a page at random with no collaboration, milestones, or test plans), and $1000 buys ~3 hours of cryptanalysis work if you source it from software security people instead of actual cryptographers (who bill north of $450/hr).

I have no idea who you are and so I don't want to sound like I'm offended by what you've posted. But you are like the 100th person to staple SJCL onto a web app and posit that they've created something more secure than a private wiki. Actual professional cryptographers have addressed similar claims in the past. Here's Nate Lawson:

http://rdist.root.org/2010/11/29/final-post-on-javascript-cr...

Instead of the brinksmanship of offering a contest, why don't you instead just listen to the arguments people are making and try to learn from them?

Triple bonus points for noting that AES and SHA3 were the products of design contests, after Schneier wrote this, and then observing the differences between those design contests and the one at the top of this thread.

Some famous contests: RSA_Factoring_Challenge[1], RSA_Secret-Key_Challenge[2], Pwn2Own[3]. In fact, the RSA Secret-Key Challenge was organised "with the intent of helping to demonstrate the relative security of different encryption algorithms." Now they are providing way more money, but overall I think that while contests dont prove anything, they certainly help improve consumer confidence and potentially help fix non-critical security bugs.

[1]http://en.wikipedia.org/wiki/RSA_Factoring_Challenge

[2]http://en.wikipedia.org/wiki/RSA_Secret-Key_Challenge

[3]http://en.wikipedia.org/wiki/Pwn2Own

That article provides a very solid argument for javascript crypto having no advantages over server-side crypto and being harder to do without errors.

But just because it has no advantages doesn't mean it won't work. A three wheeled car will still get me from point A to point B.

I agree it only proves security up to a certain value. Would you be happier if I increased the reward?

Regardless, what do you think of someone who publicly calls something a terribly insecure idea, and then reacts with snark and doesn't actually attempt to crack the system when the opportunity is put before him by someone willing to bend over backwards to help him crack it?

Propose a plan to actually crack the system. Do you want the database? Do you want to control the network where I log in?

Imagine if people built bridges the way you propose building secure software. "What do you think of someone who publicly calls a new bridge design unsafe, and then reacts with snark and doesn't actually attempt to destroy the bridge when the opportunity is put before her by someone willing to bend over backwards to help her do it?"

Engineering doesn't work that way. Your proposed solution doesn't become more sound simply because you feel aggrieved at the way people react to it.

Also: it's deeply dishonest to suggest that the only reaction you've received to this design is "snark". As I pointed out above, with a link and everything, and as you yourself acknowledged in your original post, you've been given a litany of reasons why your proposed design is flawed. You just don't seem to like hearing them.

If it's actually _as_ insecure as you say, why not collect your $1000? You'd make it back even more with gained reputation of your status as a security expert.

Instead, I'm inclined to believe you just can't.

I'm inclined to agree with the original poster. If it's really as deeply insecure as you claim it is, you should be able to crack it in less than the 3 hours of time (that you also claim the proposed prize is worth). The OP even offered to increased the prize money if you think it'll take longer than that.

In other words, sometimes, you have to put your money where your mouth is. The OP is doing that. You're not.

I'd expect them to propose a scenario that could be tested either with software or a miniature. You're under no obligation to but examples are persuasive. Feynman's ice water demonstration convinced far more people than his well-reasoned appendix.

I'm attempting to give those who believe that JS crypto should never be used a way to make a clear public demonstration. What better target could you ask for? A web application hacked together in a few hours by someone with no training in computer security who isn't even a professional software engineer and who is willing to arrange scenarios favorable to the attacker.

I'm not aggrieved by the negative reaction. I have no skin in this game. I don't earn anything if people walk away believing this idea is more secure. I just wish you wouldn't keep repeating the same canard about having to bootstrap the crypto on every use while attacking the messenger and the manner in which the message is being delivered.

I have put a sticky note on the front of my laptop. This sticky note contains a single english word.

If you can tell me this English word, I will paypal you $10.

--

Despite no one winning my "contest", my sticky-note encryption system is not particularly secure.

Ratatouille!

Don't you get it, it is a catch, the sticker contains the phrase "a single english word".

I'll happily do that. When can I swing by to chat?

Different systems are secure against different threats. Sticky notes are secure against people who can't get physical access to their location.

The question in this case is what attacks this experiment is secure against.

You posted your message because you said you wanted the discussion, and to see the flaws in your argument. But when people are answering you, you seem to be working hard to ignore them ;)

I've taken the sticky note down. It had the word "contrite"

There were plenty of exploits you could have done, without having local access to my machine. Just one example- If you view my profile, you can determine the company I work for. Use linked/etc to message someone there, and offer to split my generous reward with them, if they tell you the word.

Just because no one took me up on my offer doesn't mean my sticky-note was secure.

Yes, of course it was a silly "contest", but that's the point - Contests like this don't prove anything at all about how strong or weak your solution is.

I welcome the discussion and am learning what I can from it. I was hoping for an exploit. So far one person has proposed one that may work.

Those are creative solutions to your contest. I should have been cleverer.

>You posted your message because you said you wanted the discussion, and to see the flaws in your argument. But when people are answering you, you seem to be working hard to ignore them ;)

Where are these people that are actually suggesting plausible attacks rather than just mocking the idea of a contest? I don't see them.

The word was 'contrite'. You didn't set a time limit on your contest.

calm down and let them have some fun mr. security expert.

Bruce Schneier is not God. stop kissing his butt. ;)

By the way....

"3. Contest Prizes are rarely good incentives..."

meanwhile...

"Our Twofish cryptanalysis contest offers a $10K prize..."

"2. The analysis is not controlled..."

meanwhile....

"..There are no arbitrary definitions of what a winning analysis is...We are simply rewarding the most successful cryptanalysis research result, whatever it may be and however successful it is..."

LMAO...this is from the same article!

"The above three reasons are generalizations. There are exceptions, but they are few and far between. The RSA challenges, both their factoring challenges and their symmetric brute-force challenges, are fair and good contests. These contests are successful not because the prize money is an incentive to factor numbers or build brute-force cracking machines, but because researchers are already interested in factoring and brute-force cracking. The contests simply provide a spotlight for what was already an interesting endeavor. The AES contest, although more a competition than a cryptanalysis contest, is also fair.

Our Twofish cryptanalysis contest offers a $10K prize for the best negative comments on Twofish that aren't written by the authors. There are no arbitrary definitions of what a winning analysis is. There is no ciphertext to break or keys to recover. We are simply rewarding the most successful cryptanalysis research result, whatever it may be and however successful it is (or is not). Again, the contest is fair because 1) the algorithm is completely specified, 2) there are no arbitrary definition of what winning means, and 3) the algorithm is public domain."

Our Twofish cryptanalysis contest offers a $10K prize for the best negative comments on Twofish that aren't written by the authors. There are no arbitrary definitions of what a winning analysis is. There is no ciphertext to break or keys to recover. We are simply rewarding the most successful cryptanalysis research result, whatever it may be and however successful it is (or is not). Again, the contest is fair because 1) the algorithm is completely specified, 2) there are no arbitrary definition of what winning means, and 3) the algorithm is public domain."

This contest encrypted something with AES, stuck it in a database, attached a web app to it, stapled SJCL to the web app, and then said "decrypt the encrypted data in the database and I'll give you $1000".

No, I've invited you to propose attacks and help you carry them out. Do you want to try to use a malicious network to inject code to steal my password? Find a vulnerability in one of the endpoints to take control of the server? Try to find a cross-site attack?

Propose a practical attack against this app and I'll help you carry it out.

But the claims about JS crypto deal with the users' security in live settings: they usually are not related to "app" issues but users', which is not the same.

So? You guys wrote an article about it...

http://www.matasano.com/articles/javascript-cryptography/

"SJCL is great work, but you can't use it securely in a browser for all the reasons we've given in this document.

SJCL is also practically the only example of a trustworthy crypto library written in Javascript, and it's extremely young.

The authors of SJCL themselves say, "Unfortunately, this is not as great as in desktop applications because it is not feasible to completely protect against code injection, malicious servers and side-channel attacks." That last example is a killer: what they're really saying is, "we don't know enough about Javascript runtimes to know whether we can securely host cryptography on them". Again, that's painful-but-tolerable in a server-side application, where you can always call out to native code as a workaround. It's death to a browser."

I'm lost. What are you trying to say here?

I think what is trying to say, is: let peoples learn by their mistakes. I really don't understand your focus on making a kind of witch hunt anytime someone try to learn and implement crypto. It is certainly the responsability of the developer to try not making mistakes but it's also the responsability of the user to know what to expect of what he is going to use. And I think most people on HN are smart enough to consider this kind of post with a grain of salt and not expect too much of it.

It's starting to piss me off when people say I'm on a witch hunt for people learning crypto. I'm obviously not; I'm in the middle of dealing with literally hundreds of 1-1 conversations with strangers to help them learn crypto:

http://www.matasano.com/articles/crypto-challenges/

My problem is with people who don't want to learn crypto, but do want to use it anyways.

> I really don't understand your focus on making a kind of witch hunt anytime someone try to learn and implement crypto.

There's a stark contrast between someone wanting to learn crypto (and being humble about the process) and someone who's new to crypto but being anything but humble.

so? it was interesting. don't be a hater.

That is what I understood but it seemed too dumb to me. But it looks like it. That is not browser security, that is just AES & or possibly server-side (what id has the item?).

I am at a loss.

Just a bunch of pompous platitudes. As the oft-cited matasano article on JS crypto. I didn't know crypto professionals needed to be so self-aggrandizing.

Have you considered asking Bruce Schneier? Because the rebuttal to "here's a contest, show that what I'm doing is insecure" is his, not mine.

> As the oft-cited matasano article on JS crypto

Considering that tptacek is a Matasano researcher, why wouldn't you address the specific issues you have with the article? It doesn't seem filled with platitudes, and it's not self-referential at all, much less self-aggrandizing.

What is self-aggrandizing are people offering crypto snake-oil with bluster and boasts and contests instead of entering into the dialog and state of research. It's a very good thing that the establishment is skeptical and careful about this sort of thing.

The weirdest part is that everyone seems to take this so personally. Sarah Flannery, a teenager at the time, took it better when her crypto algorithm was broken. Her attempt was no slouch either.

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