SSL And The Future Of Authenticity

http://www.thoughtcrime.org/blog/ssl-and-the-future-of-authenticity/

by gnosis • 13 years ago

90 48 13 years ago

I completely agree with moxie marlinspike but...

This article is two years old, and the effort behind the convergence project (http://convergence.io) seems to have moved on to tack (http://tack.io)

mistertrotsky• 13 years ago

Fuck yeah, I wasn't aware of these projects. I thought the article was exceptionally good and I'm very pleased that there are people taking the initiative to actually do the hard work in search of resolution for the problems detailed. Thank you.

pi18n• 13 years ago

It's pretty clear and well-written, so I think its going to be worth reading to explain why the system is wrong for as long as our system is a list of permanently trusted CA's. There's no reason I should be trusting all those CA's to sign for anything on the internet forever.

kijin5• 13 years ago

No CA is permanently trusted. CA certificates expire like any other SSL certificate, and most of the CA certificates that my browser trusts will expire in about 10 years. In addition, browser vendors like Mozilla routinely make decisions to add and delete CA certificates.

teeja• 13 years ago

A great time to raise these questions. What reason have we ever had to trust any of these "authorities" (let alone the deteriorating state of the field, e.g. the recent Turkish fiasco)? Without a firm answer for that question, SSL is reduced to magic thinking.

kaoD10• 13 years ago

Because there's no alternative. Either you trust the authorities or live in a constant fear that the other parties' certificates are hacker-crafted.

ashkav• 13 years ago

I'm no expert at cryptography and all that stuff, but i find the model of the httpsy link quite interesting. You include the identity of the site you're linking to in an extended httpsy address, so that you can be sure that you land on the site you linked to.

The beauty of the Idea is that it democratizes the trust domain. It creates a web where ordinary people decide whom they trust simply by putting down httpsy-Links.

kijin5• 13 years ago

> total ripoff and also insecure

I pay less for SSL certificates per year than I do for the domains I use them on. You can get a free certificate from StartSSL if you're just playing, or an $8 certificate from Comodo if you're more serious. Some registrars (cough Gandi cough) even include a free SSL certificate with every domain.

So the "total ripoff" thing has been all but solved by market competition (unless you prefer to splurge on a $800 certificate that doesn't do anything a $8 certificate can't do). It's really just the "insecure" part that needs to be addressed.

rubbingalcohol• 13 years ago

It makes sense that the more CA's you allow into the market the less of a "total ripoff" you'd have due to competition, but intuitively there would be more of a problem on the "insecure" side due to fly-by-night companies with weak security. I don't see this as the main problem though.

In practice I feel like the whole CA system is flawed because you're trusting the CA based on the authority assigned to it by a higher governing body, a governing body you can't necessarily be sure isn't getting some blank-check signing superpowers from the CA and doing man-in-the-middle attacks on persons of interest with bogus certs. I can't necessarily trust that the authorities have my best interests in mind so I can't trust the CA signing system.

I look forward to the author's proposed solution(s) to this problem.

pzb• 13 years ago

In what way is a StartSSL certificate any different from a Comodo certificate? What makes StartSSL only usable for "playing"?

chmike• 13 years ago

Free StartSSL are for non commercial usage. This is, I guess, what he means by "for playing", I don't know for comodo, if their certificates can be use for commercial applications.

kijin5• 13 years ago

StartSSL is recognized by OS X 10.5 or later, and Windows 7 or later. Older OSes might not recognize it if the user has missed any updates.

I'm OK with showing IE6/7 users a polite suggestion to upgrade, but a certificate error looks unprofessional. In addition, Chrome on XP is also affected (if the user has missed the CA update) because Chrome doesn't carry its own list of trusted CAs.

kaoD10• 13 years ago

> on a $800 certificate that doesn't do anything a $8 certificate can't do

Unless you need *.domain.tld certificates.

DoubleMalt2• 13 years ago

You can get unlimited *.domain.tld certificates from StartSSL after inexpensive verfication step. But don't tell anyone.

skrause• 13 years ago

Where can I find those $8 certificate? https://www.positivessl.com/ only shows me "from €49.00/ year".

james-skemp• 13 years ago

Name cheap has them. http://www.namecheap.com/ssl-certificates/comodo/positivessl...

Might be thinking of that.

anologwintermut• 13 years ago

Trust authority only works if users are willing to actually make trust decisions. Since they are not, whatever trust authorities chrome, firefox, and IE ship with will end up being a default single point of failure, target for compromise, and point of corruption.

Pinning certificates or using something like Namecoin to maintain a key to human identifier mapping seems like a better idea.

sebcat• 13 years ago

What if confidentiality and authenticity would be handled by IPSec/DNSSEC instead of using solutions at the transport layer? This is not my idea, or new, but it makes more sense to me. Why do we move towards implementing security measures higher up in the abstraction layers when it should be a core part in any system?

nextstep• 13 years ago

It's too bad you didn't read the article. He answers your exact question.

acabal2• 13 years ago

I've been wondering lately why SSL ties both encryption between two parties and the identies of those two parties together. A genuine question borne of genuine ignorance on my part: why are these two concepts tied to the the same protocol?

Why can't we have two separate systems? One to ensure two parties communicate secretly with each other, and another to somehow verify the real-life identities of those two parties? Why did those to seemingly separate concepts evolve as one?

If we could separate them, it seems we could solve a lot of low-level security problems online: sites could have cost-free, CA-free self-signed certs to ensure only that packets between the client and server are secure/private; then separately, there could be a different system to ensure that the client is really, truly communicating with the Bank of Their Nation, Inc., and not a scammer from Nigeria.

How did identity and privacy become conflated, and how can we separate those to provide monetary-cost-free eavesdropping protection in the future?

kaoD10• 13 years ago

Because encryption's purpose is completely defeated if you don't know who you are talking to.

A man in the middle could easily reproduce your data to the other party (and viceversa) if you are not sure you are talking to the correct party.

How could you be sure you're doing

  A -(encrypted)-> B

and not

  A -(encrypted)-> MITM -(encrypted)-> B

You can't, so you'd better ditch the encryption and just talk plaintext.

Encryption relies on the fact that you have a signature from B who says "hey, I'm REALLY B, you're talking to me directly, here's my public key so you can talk only to me and nobody else can read the data inbetween".

That's where CAs come into play: they're the authorities that certify that B's signature/public key is actually tied to the domain you think you're talking to.

> CA-free self-signed certs to ensure only that packets between the client and server are secure/private

What's the difference of a self-signed certificate from www.gmail.com and a self-signed certificate from RandomHacker who says he's www.gmail.com ?

They look the same.

So... both concepts are actually separate already (e.g. did you ever trust a certificate manually in your browser?), but it's pretty pointless when you ignore CAs and therefore don't know if the certificate is real or crafted.

pyre• 13 years ago

  | They look the same

Unless you have a known, valid signature.

acabal2• 13 years ago

So forgive my denseness here, but that can still be broken down into two separate protocols, right? 1) I wish to communicate with foo.com privately, regardless of whether foo.com is really who foo.com claims to be; that is, one time foo.com might be 192.168.0.0, and the next time it might be 192.168.0.1; but either way, regardless of who I'm truly communicating with, I can at least be sure that nobody but the recipient can decode the packets. Then, 2) I can guarantee everything in (1), plus that my the packets I exchange with foo.com are truly the foo.com that resides at 123 Main St., USA.

An analogy might be: 1) I seal a letter in an envelope, and the postal service guarantees that it will arrive at the address I specify, regardless of the human that opens the letter at that address; and 2) I seal a letter in an envelope, and the postal service guarantees that not only will the letter arrive at the address I specify, but that it will only be opened by the human I specify, who is identified by his postal-service-issued ID number.

andrewflnr• 13 years ago

I never got that deep into SSL, but I seem to recall there are cipher suites that allow unauthenticated encryption. I could be wrong. Also, what everyone else said.

wyager2• 13 years ago

Seems to me like Namecoin is a practical, secure method of distributed identification and verification. It's basically a secure P2P key:value store based off of Bitcoin's method of operation. Its original intent was to replace DNS (the website name is the key, the IP address is the value), but I see no reason why we couldn't also use it to host public keys.

twoodfin• 13 years ago

How does it stop me from saying "Bank of America's public key is <my public key>"?

Dylan168072• 13 years ago

Nothing. The same way you can go buy iamthebankofamerica.com for a couple bucks and put all the keys you like on it. But once you go to the actual Bank of America domain record you'll get back the real certificates.

wyager2• 13 years ago

BoA would have to buy the rights to that name from whoever got it before them.

7952• 13 years ago

Require people to submit a public key and two factor serial number during domain purchase, then use that key to sign individual server certificates. If you loose the key or two factor device you loose SSL on the domain, no exceptions. When I go to google.com all I really care is that it is the same site that I visited yesterday. The current SSL scheme gives no such assurance.

SSL And The Future Of Authenticity

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