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> Certificate Transparency is a solution CT would not have prevented these attacks. Google would be exactly where they are right now: knowing who issued cert,

> Certificate Transparency is a solution CT would not have prevented these attacks. Google would be exactly where they are right now: knowing who issued cert, and that's it. Short form: https://github.com/okTurtles/dnschain/blob/master/docs/Comparison.md https://github.com/okTurtles/dnschain/blob/master/docs/Compa... Long form: https://blog.okturtles.com/2014/09/the-trouble-with-certificate-transparency/ https://blog.okturtles.com/2014/09/the-trouble-with-certific... (EDIT: How about an honest discussion instead of a downvote? If you disagree, you are welcome to explain why.)

geofft 12y ago
Given the operational difficulty of implementing a transparently-MITMing proxy in a Certificate Transparency regime, I'm not sure you can say with certainty that it wouldn't have prevented this attack. Every time you want to MITM a new site, you need to contact some number of auditors before you can complete the connection. That sounds difficult to implement reliably and quickly enough for a MITM to work. (Not to mention that most off-the-shelf MITM proxies will intentionally not implement this, since the use case for legitimate MITM proxying involves using site-specific CAs, not globally-valid CAs, so you'd have to deploy custom code to go talk to the auditors. And I somehow have doubts that a robust, black-hat MITM proxy solution will emerge, given that it probably will have only a handful of users at any given time.) In any case, it is certainly not a perfect solution. But it is a solution. I've read that okTurtles blog post before. Insofar as it points out that CT has limitations, it's generally right. But the okTurtles scheme is much worse: if a certificate gets compromised, the only recourse is to pick a new website name. I think it's likely that there is no perfect solution here. CT makes no claims for perfection, but it's a pretty good imperfect solution, and I think we need that more than we need a nonexistent perfect solution. BTW: "Resist commenting about being downvoted. It never does any good, and it makes boring reading."
- itistoday2 12y ago
  > Given the operational difficulty of implementing a transparently-MITMing proxy in a Certificate Transparency regime, I'm not sure you can say with certainty that it wouldn't have prevented this attack. Every time you want to MITM a new site, you need to contact some number of auditors before you can complete the connection. 1. Certs don't need to include SCTs, so, end of story. 2. Even if that was a requirement, they can be faked just like the certificate. > In any case, it is certainly not a perfect solution. But it is a solution. It doesn't prevent MITM attacks (even Google acknowledges that), so it's not a solution (if preventing attacks is what you want). > But the okTurtles scheme is much worse: if a certificate gets compromised, the only recourse is to pick a new website name. Certificates are not associated with the key to modify the blockchain entry. So if a certificate gets compromised, you can immediately fix it by updating the blockchain entry. > BTW: "Resist commenting about being downvoted. It never does any good, and it makes boring reading." If people downvote me for no good reason, I'll point it out to them. Doesn't matter to me if it bores them. If that's a problem maybe they shouldn't downvote in the first place? :P
  - skj 12y ago
    > Doesn't matter to me if it bores them. If that's a problem maybe they shouldn't downvote in the first place? Perhaps the downvotes are because it bores them? I guess it shouldn't matter to you that you get downvoted, either.
    - itistoday2 12y ago
      > Perhaps the downvotes are because it bores them? I guess it shouldn't matter to you that you get downvoted, either. Either folks want this problem to be solved, or they don't.
      - geofft 12y ago
        I am confident that if DNSChain is such an obviously good solution, it will be evangelized by at least one person who doesn't complain about being downvoted, or claim that people clearly don't want security. Are you Tao Effect? I've seen you on messaging@moderncrypto, and you have trouble staying on topic. I'd have been more inclined to give you the benefit of the doubt if you were some second person in the world who thought DNSChain was a good idea, but I've only ever seen one person evangelize this concept (in email, on the website, and now in HN comments). As general advice, if you try a bit harder to respect the conventions of the fora you use to evangelize things, no matter how reasonable or unreasonable you think the conventions are, you're likely to win more hearts and minds. And you do want to win hearts and minds, don't you? Either you want this problem to be solved (and you have the perfect solution, if only people would listen), or you don't.
        itistoday2 12y ago
        When you run out of legitimate arguments resort to personal attacks, got it. The number of people on Earth who've spent the time studying Certificate Transparency in depth could probably be counted on two hands. You and I are two of them. That leaves ~8 other people (who are probably not reading these threads) to comment. I'm grateful to everyone who's taken the time to support DNSChain, Namecoin, and related projects by writing about them, podcasting, tweeting, blogging, contributing code, etc. https://github.com/okTurtles/dnschain#community https://github.com/okTurtles/dnschain#community This certainly requires community support.
- geofft 12y ago
  > Not to mention that most off-the-shelf MITM proxies will intentionally not implement this To add on to this: the certificate was generated from a Palo Alto Networks device. https://groups.google.com/forum/#!topic/mozilla.dev.security.policy/czwlDNbwHXM https://groups.google.com/forum/#!topic/mozilla.dev.security... If Palo Alto aren't willing to implement CT, which I'm pretty sure they aren't because they're a legitimate company whose business isn't driven by people who abuse globally-valid certificates, then (regardless of whether SCTs can be forged in theory) that alone would have prevented the attack.
sanxiyn 12y ago
It is not downvoted (gray) any more.

geofft 12y ago

Given the operational difficulty of implementing a transparently-MITMing proxy in a Certificate Transparency regime, I'm not sure you can say with certainty that it wouldn't have prevented this attack. Every time you want to MITM a new site, you need to contact some number of auditors before you can complete the connection. That sounds difficult to implement reliably and quickly enough for a MITM to work. (Not to mention that most off-the-shelf MITM proxies will intentionally not implement this, since the use case for legitimate MITM proxying involves using site-specific CAs, not globally-valid CAs, so you'd have to deploy custom code to go talk to the auditors. And I somehow have doubts that a robust, black-hat MITM proxy solution will emerge, given that it probably will have only a handful of users at any given time.) In any case, it is certainly not a perfect solution. But it is a solution. I've read that okTurtles blog post before. Insofar as it points out that CT has limitations, it's generally right. But the okTurtles scheme is much worse: if a certificate gets compromised, the only recourse is to pick a new website name. I think it's likely that there is no perfect solution here. CT makes no claims for perfection, but it's a pretty good imperfect solution, and I think we need that more than we need a nonexistent perfect solution. BTW: "Resist commenting about being downvoted. It never does any good, and it makes boring reading."

itistoday2 12y ago
> Given the operational difficulty of implementing a transparently-MITMing proxy in a Certificate Transparency regime, I'm not sure you can say with certainty that it wouldn't have prevented this attack. Every time you want to MITM a new site, you need to contact some number of auditors before you can complete the connection. 1. Certs don't need to include SCTs, so, end of story. 2. Even if that was a requirement, they can be faked just like the certificate. > In any case, it is certainly not a perfect solution. But it is a solution. It doesn't prevent MITM attacks (even Google acknowledges that), so it's not a solution (if preventing attacks is what you want). > But the okTurtles scheme is much worse: if a certificate gets compromised, the only recourse is to pick a new website name. Certificates are not associated with the key to modify the blockchain entry. So if a certificate gets compromised, you can immediately fix it by updating the blockchain entry. > BTW: "Resist commenting about being downvoted. It never does any good, and it makes boring reading." If people downvote me for no good reason, I'll point it out to them. Doesn't matter to me if it bores them. If that's a problem maybe they shouldn't downvote in the first place? :P
- skj 12y ago
  > Doesn't matter to me if it bores them. If that's a problem maybe they shouldn't downvote in the first place? Perhaps the downvotes are because it bores them? I guess it shouldn't matter to you that you get downvoted, either.
  - itistoday2 12y ago
    > Perhaps the downvotes are because it bores them? I guess it shouldn't matter to you that you get downvoted, either. Either folks want this problem to be solved, or they don't.
    - geofft 12y ago
      I am confident that if DNSChain is such an obviously good solution, it will be evangelized by at least one person who doesn't complain about being downvoted, or claim that people clearly don't want security. Are you Tao Effect? I've seen you on messaging@moderncrypto, and you have trouble staying on topic. I'd have been more inclined to give you the benefit of the doubt if you were some second person in the world who thought DNSChain was a good idea, but I've only ever seen one person evangelize this concept (in email, on the website, and now in HN comments). As general advice, if you try a bit harder to respect the conventions of the fora you use to evangelize things, no matter how reasonable or unreasonable you think the conventions are, you're likely to win more hearts and minds. And you do want to win hearts and minds, don't you? Either you want this problem to be solved (and you have the perfect solution, if only people would listen), or you don't.
      - itistoday2 12y ago
        When you run out of legitimate arguments resort to personal attacks, got it. The number of people on Earth who've spent the time studying Certificate Transparency in depth could probably be counted on two hands. You and I are two of them. That leaves ~8 other people (who are probably not reading these threads) to comment. I'm grateful to everyone who's taken the time to support DNSChain, Namecoin, and related projects by writing about them, podcasting, tweeting, blogging, contributing code, etc. https://github.com/okTurtles/dnschain#community https://github.com/okTurtles/dnschain#community This certainly requires community support.
geofft 12y ago
> Not to mention that most off-the-shelf MITM proxies will intentionally not implement this To add on to this: the certificate was generated from a Palo Alto Networks device. https://groups.google.com/forum/#!topic/mozilla.dev.security.policy/czwlDNbwHXM https://groups.google.com/forum/#!topic/mozilla.dev.security... If Palo Alto aren't willing to implement CT, which I'm pretty sure they aren't because they're a legitimate company whose business isn't driven by people who abuse globally-valid certificates, then (regardless of whether SCTs can be forged in theory) that alone would have prevented the attack.

sanxiyn 12y ago

It is not downvoted (gray) any more.