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Telegram’s Cryptanalysis Contest

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Re: Telegram’s Cryptanalysis Contest

#131

Post by phaus »

paveldurov wrote: post #120
jaxb wrote: post #116

Earlier quoted context omitted.

Do you truly need to ad-hominem attack tptacek? You sound pretty much like pseudoscientists when they blame mainstream science being too rigid and not accepting their groundbreaking theories.

Scientific approach is exactly what I'm calling for here. When a cryptographer resorts to arguments like "this algorithm won't work because it is not common/modern/accepted" without providing an exact way to break it, it doesn't sound like scientific approach to me. It's more like the religious mindset of someone who rigidly worships some limited list of tools (e.g. "NSA Suite B Cryptography") and punishes anyone who…

A large number of people who know what they are talking about have stated to you in the clearest terms possible that when it comes to cryptography and security systems, it is appropriate to place the burden of proof on the creators. It isn't an opinion, its a fact agreed on by every competent security practitioner on the planet. If you are going to continue to ignore this, no one is going to take anything you say about cryptography seriously.

Its not about dogma, its about safety. The fact that you fail to understand that is a testament to your inability to contribute to a meaningful conversation about security.

Re: Telegram’s Cryptanalysis Contest

#132

Post by phaus »

kayoone wrote: post #24
Confusion wrote: post #14

Earlier quoted context omitted.

An expert on trees: This oak is probably diseased. It has discolorations on some of the leaves and the bark is much looser than normal. I think it should be thoroughly investigated or perhaps just cut it down to be safe. kayoone, knowing nothing of trees: "some strong claims in there for not really proving that the tree is indeed diseased."

And you obviously know that i know nothing of on the subject?

I think that most people realized this upon reading your other comment.

You are either entirely unfamiliar with cryptography or you misunderstand a great deal of what you think you do know.

Re: Telegram’s Cryptanalysis Contest

#133

Post by [deleted] »

forgottenpass wrote: post #73
TelegramApp wrote: post #52

The contest, as proposed by Pavel, while limited for the moment, does cover an important issue as far as our users are concerned. And the scope will naturally expand with time, should Telegram be invulnerable under the current conditions (see contest FAQ: http://core.telegram.org/contestfaq ). Quoting a post by Pavel here on HN: "Telegram will always be interested in creating incentives for the crypto-community to ch…

Lets assume, just for the sake of argument, that your encryption system and trust model are fine. Good. Great even. So, you have a great system and cryptographers are giving you free advice on how to make it even better, why aren't you taking it? Are they wrong?

[deleted]

Re: Telegram’s Cryptanalysis Contest

#134

Post by phaus »

kbenson wrote: post #72
rlx0x wrote: post #69

Earlier quoted context omitted.

did he pay to be the top voted comment, or are the HN readers really that stupid and voted him up? (Did he really just argue that sha1 isn't broken? ohmy)

Maybe because it appears to be an official response so is relevant , regardless of whether people think it's entirely correct. That can be a good reason to upvote, IMO.

IMO, because its either intentionally misleading or painfully uninformed, the fact that its info that came directly from the horse's mouth isn't a very good reason to up-vote.

Re: Telegram’s Cryptanalysis Contest

#135

Post by jaxb »

paveldurov wrote: post #120
jaxb wrote: post #116

Earlier quoted context omitted.

Do you truly need to ad-hominem attack tptacek? You sound pretty much like pseudoscientists when they blame mainstream science being too rigid and not accepting their groundbreaking theories.

Scientific approach is exactly what I'm calling for here. When a cryptographer resorts to arguments like "this algorithm won't work because it is not common/modern/accepted" without providing an exact way to break it, it doesn't sound like scientific approach to me. It's more like the religious mindset of someone who rigidly worships some limited list of tools (e.g. "NSA Suite B Cryptography") and punishes anyone who…

I'm sorry but I have to ask:

Can you prove that you indeed are Pavel Durov of VK?

Re: Telegram’s Cryptanalysis Contest

#136

Post by paveldurov »

tptacek wrote: post #129
paveldurov wrote: post #120

Earlier quoted context omitted.

Scientific approach is exactly what I'm calling for here. When a cryptographer resorts to arguments like "this algorithm won't work because it is not common/modern/accepted" without providing an exact way to break it, it doesn't sound like scientific approach to me. It's more like the religious mindset of someone who rigidly worships some limited list of tools (e.g. "NSA Suite B Cryptography") and punishes anyone who…

I like this. "I'm calling for a scientific approach". Meaning, we throw out the last 20 years of scientific work on cryptography and start over from first principles, because the weight of the literature is inconvenient for your argument. It's an interesting tactic you've invented, and I'm surprised I haven't seen it in client change denial posts.

Well, when some of this "research" you promote ends up being backdoors planted by NSA (http://reut.rs/192XWwG), one has to be cautious.

Personally, I am more comfortable with 70s algorithms like Diffie-Hellman that have known and well-researched weaknesses. The "modern" algorithms actively promoted by US security firms after 9/11 are not time-tested, to say the least.

Re: Telegram’s Cryptanalysis Contest

#137

Post by xerophtye »

B-Con wrote: post #97
vitalyny wrote: post #68

Earlier quoted context omitted.

Sorry I didn't respond to that. No, I'm not associated with Telegram in any way. And I'm not crypto professional :) I totally understand what Telegram critics are saying, but in every article there's always a note "Please use TextSecure, don't use Telegram". By how it looks, it seems to be a way to market TextSecure and not to discover Telegram's security flaws. And critics rarely respond to Telegram team's comments…

> but in every article there's always a note "Please use TextSecure, don't use Telegram". This is very common in the security field. Good crypto/security software is often not very straight-forward for the public to find. They're usually run by competent developers doing the work for free and don't tend to have big PR budgets or do a lot of advertising. The product is findable, but they can be overshadowed by snake-o…

>Yes, it helps Y piggie-back a bit off the popularity of X, but that's Y's fault being being bad enough to be disparaged.

Correction: Yes, it helps Y piggie-back a bit off the popularity (or notoriety) of X, but that's X's fault being being bad enough to be disparaged.

Re: Telegram’s Cryptanalysis Contest

#138

Post by jaekwon »

tptacek wrote: post #76
TelegramApp wrote: post #52

The contest, as proposed by Pavel, while limited for the moment, does cover an important issue as far as our users are concerned. And the scope will naturally expand with time, should Telegram be invulnerable under the current conditions (see contest FAQ: http://core.telegram.org/contestfaq ). Quoting a post by Pavel here on HN: "Telegram will always be interested in creating incentives for the crypto-community to ch…

I'm worried that to people unfamiliar with modern crypto, the diagram of your protocol and the "technical FAQ" might sound credible or even convincing. But it is not. The message integrity protection this system describes is not up to modern standards. The system seems to use SHA1, which is a fault for a new system (no new system should use SHA1), but that's not the biggest problem; the biggest problem is that the SH…

> the biggest problem is that the SHA1 digest of a message is not an authenticator of that message, because an attacker can generate the same digest given only the contents of the message.

Curious, if the secret token comes after the message & there is proper delimiters to separate the message from the secret, where is the vulnerability?

Take a look at this link: https://blog.jcoglan.com/2012/06/09/why-you-should-never-use...

Am I correct to think that the example cited is bad? It appears that it would be a strong MAC because of the reasons that I cited.

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