5 ms·

In an ideal world where we rebuilt the whole stack from scratch, the DNS system would securely distribute key material alongside IP addresses and CAs wouldn't b

In an ideal world where we rebuilt the whole stack from scratch, the DNS system would securely distribute key material alongside IP addresses and CAs wouldn't be needed. Most modern DNS alternatives (Handshake, Namecoin, etc) do exactly this, but it's very unlikely any of them will be usurping DNS anytime soon, and DNS's attempts to implement similar features have been thus far unsuccessful.

tptacek 2y ago
People who idealize this kind of solution should remember that by overloading core Internet infrastructure (which is what name resolution is) with a PKI, they're dooming any realistic mechanism that could revoke trust in the infrastructure operators. You can't "distrust" .com. But the browsers could distrust Verisign, because Verisign had competitors, and customers could switch transparently. Browser root programs also used this leverage to establish transparency logs (though: some hypothetical blockchain name thingy could give you that automatically, I guess; forget about it with the real DNS though).
- transfire 2y ago
  Who cares? What does a certificate tell me other than someone paid for a certificate. And what do certificate buyers gain? The ability for their site to be revoked or expired and thus no longer work. I’d like to corrected.
  - brazzy 2y ago
    Are you seriously not aware of Let's Encrypt? https://letsencrypt.org/ https://letsencrypt.org/ Nobody has really had to pay for certificates for quite a number of years. What certificates get you, as both a website owner and user, is security against man-in-the-middle attacks, which would otherwise be quite trivial, and which would completely defeat the purpose of using encryption.
    - transfire 2y ago
      As long as Let’s Encrypt is still around. I find it hard to believe there is no way to secure without requiring an authority in the middle.
  - squiggleblaz 2y ago
    A certificate authority is an organisation that pays good money to make sure that their internet connection is not being subjected to MITMs. They put vastly more resources into that than you can. A certificate is evidence that the server you're connected to has a secret that was also possessed by the server that the certificate authority connected to. This means that whether or not you're subject to MITMs, at least you don't seem to be getting MITMed right now. The importance of certificates is quite clear if you were around on the web in the last days before universal HTTPS became a thing. You would connect to the internet, and you would somehow notice that the ISP you're connected to had modified the website you're accessing.
    - Ajedi32 2y ago
      > pays good money to make sure that their internet connection is not being subjected to MITMs Is that actually true? I mean, obviously CAs aren't validating DNS challenges over coffee shop Wi-Fi so it's probably less likely to be MITMd than your laptop, but I don't think the BRs require any special precautions to assure that the CA's ISP isn't being MITMd, do they?
- ysleepy 2y ago
  .com can issue arbitrary certificates right now, they control what DNS info is given to the CAs. So I don't quite see the change apart from people not talking about that threat vector atm.
  - tptacek 2y ago
    Get one to issue a Google.com certificate and see what happens.
    - throwaway2037 2y ago
      This is a great point. For all of the "technically correct" arguments going on here, this one is the most practical counterpoint. Yes, in theory, Verisign (now Symantec) could issue some insane wildcard Google.com cert and send the public-private key pair to you personally. In practice, this would never happen, because it is a corporation with rules and security policies that forbid it. Thinking deeper about it: Verisign (now Symantec) must have some insanely good security, because every black hat nation state actor would love to break into on their cert issuance servers and export a bunch of legit signed certs to run man-in-the-middle attacks against major email providers. (I'm pretty sure this already happened in Netherlands.)
      - codethief 2y ago
        > every black hat nation state actor would love to break into on their cert issuance servers and export a bunch of legit signed certs to run man-in-the-middle attacks I might be misremembering but I thought one insight from the Snowden documents was that a certain three-letter agency had already accomplished that?
        9Ljdg6p8ZSzejt 2y ago
        This was DigiNotar. The breach generated around 50 certificates, including certificates for Google, Microsoft, MI6, the CIA, TOR, Mossad, Skype, Twitter, Facebook, Thawte, VeriSign, and Comodo. Here is a nice writeup for that breach: https://www.securityweek.com/hacker-had-total-control-over-diginotar-servers-report/ https://www.securityweek.com/hacker-had-total-control-over-d...

tptacek 2y ago

People who idealize this kind of solution should remember that by overloading core Internet infrastructure (which is what name resolution is) with a PKI, they're dooming any realistic mechanism that could revoke trust in the infrastructure operators. You can't "distrust" .com. But the browsers could distrust Verisign, because Verisign had competitors, and customers could switch transparently. Browser root programs also used this leverage to establish transparency logs (though: some hypothetical blockchain name thingy could give you that automatically, I guess; forget about it with the real DNS though).

transfire 2y ago
Who cares? What does a certificate tell me other than someone paid for a certificate. And what do certificate buyers gain? The ability for their site to be revoked or expired and thus no longer work. I’d like to corrected.
- brazzy 2y ago
  Are you seriously not aware of Let's Encrypt? https://letsencrypt.org/ https://letsencrypt.org/ Nobody has really had to pay for certificates for quite a number of years. What certificates get you, as both a website owner and user, is security against man-in-the-middle attacks, which would otherwise be quite trivial, and which would completely defeat the purpose of using encryption.
  - transfire 2y ago
    As long as Let’s Encrypt is still around. I find it hard to believe there is no way to secure without requiring an authority in the middle.
- squiggleblaz 2y ago
  A certificate authority is an organisation that pays good money to make sure that their internet connection is not being subjected to MITMs. They put vastly more resources into that than you can. A certificate is evidence that the server you're connected to has a secret that was also possessed by the server that the certificate authority connected to. This means that whether or not you're subject to MITMs, at least you don't seem to be getting MITMed right now. The importance of certificates is quite clear if you were around on the web in the last days before universal HTTPS became a thing. You would connect to the internet, and you would somehow notice that the ISP you're connected to had modified the website you're accessing.
  - Ajedi32 2y ago
    > pays good money to make sure that their internet connection is not being subjected to MITMs Is that actually true? I mean, obviously CAs aren't validating DNS challenges over coffee shop Wi-Fi so it's probably less likely to be MITMd than your laptop, but I don't think the BRs require any special precautions to assure that the CA's ISP isn't being MITMd, do they?
ysleepy 2y ago
.com can issue arbitrary certificates right now, they control what DNS info is given to the CAs. So I don't quite see the change apart from people not talking about that threat vector atm.
- tptacek 2y ago
  Get one to issue a Google.com certificate and see what happens.
  - throwaway2037 2y ago
    This is a great point. For all of the "technically correct" arguments going on here, this one is the most practical counterpoint. Yes, in theory, Verisign (now Symantec) could issue some insane wildcard Google.com cert and send the public-private key pair to you personally. In practice, this would never happen, because it is a corporation with rules and security policies that forbid it. Thinking deeper about it: Verisign (now Symantec) must have some insanely good security, because every black hat nation state actor would love to break into on their cert issuance servers and export a bunch of legit signed certs to run man-in-the-middle attacks against major email providers. (I'm pretty sure this already happened in Netherlands.)
    - codethief 2y ago
      > every black hat nation state actor would love to break into on their cert issuance servers and export a bunch of legit signed certs to run man-in-the-middle attacks I might be misremembering but I thought one insight from the Snowden documents was that a certain three-letter agency had already accomplished that?
      - 9Ljdg6p8ZSzejt 2y ago
        This was DigiNotar. The breach generated around 50 certificates, including certificates for Google, Microsoft, MI6, the CIA, TOR, Mossad, Skype, Twitter, Facebook, Thawte, VeriSign, and Comodo. Here is a nice writeup for that breach: https://www.securityweek.com/hacker-had-total-control-over-diginotar-servers-report/ https://www.securityweek.com/hacker-had-total-control-over-d...