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Comment by nanoscopic | Hacker News Reader

I am in the process of developing a new messaging system to address exactly that issue ( anonymous communication where it is unclear who is talking to who )

The way in which it will work is having all users of the system constantly send encrypted streams to each other ( mostly gibberish ). When you want to send a real message you simply replace the encrypted gibberish with some real content.

It will implement "onion" style repeated encryption to prevent direct links from being statistically analyzed as well.

Look for it in 6 months or so. Details will be up at circleofdistrust.com in about a month or so.

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The idea of masking real content with gibberish always seems hacky to me, and in security hacky is not a good idea. While I suspect you might be able to make it work, I think a better solution is to go to more of a bitcoin approach.

Essentially, set up a new block-chain that allows transactions to contain 'large' messages (IE. large enough for long plaintext, but probably not enough to embed videos). Then, when you want to send a message, encrypt it using the intended recipients public key, then publish the cipher-text to the blockchain.

Have you heard of bitmessage? It basically does what you suggest.

Bitmessage is essentially a torrent server where everyone gets a copy of everyone elses emails, so you get your email by downloading all emails.

Unfortunately in such a system, you have to download all emails, or request what you want in order to actual get the email you want.

The system either does not scale, or will leak information in order to remove the requirement of getting everyone elses emails.

Also, the government can collect -all- of the encrypted messages easily, and potentially eventually correlate who an anonymous id is based on their knowledge of who received messages on which day.

Basically, it sucks.

I haven't checked Bitmessage's protocals, but that it is not nessasary to identify the intended recipient. If you publish the ciphertext with no meta-data, then everyone can attempt to decrypt it. Only the intended recipient would succeed, but an ease dropper would not be able to identify who successfully decrypted the message. This raises an obvious scalability question, as you need to attempt to decrypt every message that is used in the network (in addition to simply downloading it which you have to do anyway). There are probably ways to mitigate this overhead without compromising security.

If you read the wikipedia entry is says that the destination id is required. I assume these must be created somehow and communicated to the sender before being able to receive anything.

So long as this is occurring, the way the scheme works, unless you download every message, it could be determined which id belongs to whom. Once you determine that it is easy to track originating packets to that destination since it is not an onion system.

Additionally, without side channel communication ( in person or posting that address somewhere publicly ) it is impossible to anonymously communicate to an intended recipient.

I don' t have a list of urls right now, but papers on the lack of anonymity of bitcoin and bitmessage are not hard to find. It is a very difficult problem against NSA level attackers. Masking when content is being exchanged by exchanging something on a fixed schedule seems like one of the few things that can be done to at least mask something.

Edit: OTOH, this this does just mean they attack one or both nodes if they care when content is being sent.

I still can't speak to bitmessage. but anonymity is not part of bitcoin's design goals.

Anybody building such systems today should have a plan for when (not if) they receive a National Security Letter.

Fuck the NSA.

Dear NSA: I can and will be designing a fully anonymous open source distributed messaging system that is entirely secure even if you tap every line in the world. At the very best, you will be able to accuse people just of running the software. If you don't like this, I'd advise you that your only option is to hire me and/or pay be enough money to become disinterested in finishing the creation of the software.

I take it you're not a US citizen?

Or a citizen of any country that is friends with the US, or someone who is ever planning on passing through the airport of one of those countries.

If you succeed in your endeavor, they probably would want to hire you.

I am a U.S. citizen. I still believe in freedom of speech, as well as my right to "Life, Liberty, and the pursuit of hapiness".

I am also a Libertarian, which means I don't believe in large government, due to the corruption that follows.

So long as my goals and beliefs are for freedom and privacy, the creation of secure anonymous messaging is of little interest to the NSA. Will they "like" if it is intentionally designed in a way that it could be used by criminals? No... But I should have no fear of that.

Just because guns can kill people doesn't mean you should use them for that. Just because atomic theory can be used to make large bombs doesn't mean nuclear energy is wrong. Just because pressure cookers contain heat well at pressure doesn't mean you should use them for anything besides cooking your food.

Trying to blackmail the NSA ? please let us know how it goes, it could be an interesting story.

> If you don't like this, I'd advise you that your only option is to hire me and/or pay be enough money to become disinterested in finishing the creation of the software.

So, I think you just lost my trust. You're coming at this from the wrong angle, instead of coming from a princpled stance you're approaching this as a value proposition.

Too bad, up to there you had my attention.

Check out the mixmaster anonymous remailers:

http://en.wikipedia.org/wiki/Mixmaster_anonymous_remailer

The problem with this is that it is basically this "server x supposedly receives stuff and then sends stuff on without linking identities A and B".

What if I don't trust server X to really be doing that?

What if the government contacted owner of server X and altered the software not to do that?

The system I am designing keeps anonymity without any need to trust the server. Hence the name. Don't trust anyone.

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