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There are multiple hops from you to the server. That scheme would only verify that BOTH your and the third party's initial hops haven't been simultaneously MiT

by kgo 16y ago

There are multiple hops from you to the server. That scheme would only verify that BOTH your and the third party's initial hops haven't been simultaneously MiTM'ed. It's very possible the routes overlap for several hops. And even if they didn't, I wouldn't consider hackers getting my bank info-- or governments reading my email-- the server operator's problem.

modeless 16y ago
The middle hops are much (much) harder to MITM than the initial hops. If hackers control the bank's internet connection then they get everyone's bank info, which is absolutely the bank's problem (and as such they would take measures to prevent it, like third-party monitoring of their certificates from other points on the Internet). As for governments reading email, the current CA system hardly prevents that. Under this system, you could detect MITM after the fact by using a trusted channel to compare the client's saved cert with the server's real cert. That would expose large-scale MITM tampering.
- kgo 16y ago
  I don't see any reason why it would be much harder to hit the middle hops for a MiTM attack. It certainly wouldn't be worth setting up a MiTM attack between my house and the first Comcast router my cable hits. That approach doesn't scale. Sure maybe if I'm Warren Buffet (or some mobster if we're talking about the government) it might make sense. And if they did do that, then NO source I connect to is a trusted channel, as they could MiTM any and all connections. The scheme wouldn't (always) protect you from an attacker setup somewhere in between you and your destination, like the NSA servers at AT&T, or the Firewall of China. Your trusted source could hit the same bad path. And by your own acknowledgment, the scheme doesn't protect you from a hacker breaking into a bank's data center. If a hacker is smart, and only grabs say every 100,000th credit card, how long will it take to isolate the location of the exploit? So the scheme doesn't really protect against anything with any level of confidence.
  - modeless 16y ago
    You get the initial trusted source cert through a secure channel in exactly the same way you get CA certs today, so this scheme is just as secure as SSL against an attacker who controls your entire connection. Sure, the scheme is only as good as your trusted source. But the trusted source could be very good. It could have multiple servers in different ISPs and even different countries verifying certs for you, and could use other methods of verification as well. The bank can easily check if their connections are getting MITM attacked. The hacker has to modify the certs seen by anyone who contacts the bank, even if he doesn't MITM every connection, and that would be easy for the bank to detect.
  - kalmi10 16y ago
    You are getting out of scope. A hacker breaking into a bank's data center is not at all releated to the discussion at hand.

by kgo 16y ago

modeless 16y ago

The middle hops are much (much) harder to MITM than the initial hops. If hackers control the bank's internet connection then they get everyone's bank info, which is absolutely the bank's problem (and as such they would take measures to prevent it, like third-party monitoring of their certificates from other points on the Internet). As for governments reading email, the current CA system hardly prevents that. Under this system, you could detect MITM after the fact by using a trusted channel to compare the client's saved cert with the server's real cert. That would expose large-scale MITM tampering.

kgo 16y ago
I don't see any reason why it would be much harder to hit the middle hops for a MiTM attack. It certainly wouldn't be worth setting up a MiTM attack between my house and the first Comcast router my cable hits. That approach doesn't scale. Sure maybe if I'm Warren Buffet (or some mobster if we're talking about the government) it might make sense. And if they did do that, then NO source I connect to is a trusted channel, as they could MiTM any and all connections. The scheme wouldn't (always) protect you from an attacker setup somewhere in between you and your destination, like the NSA servers at AT&T, or the Firewall of China. Your trusted source could hit the same bad path. And by your own acknowledgment, the scheme doesn't protect you from a hacker breaking into a bank's data center. If a hacker is smart, and only grabs say every 100,000th credit card, how long will it take to isolate the location of the exploit? So the scheme doesn't really protect against anything with any level of confidence.
- modeless 16y ago
  You get the initial trusted source cert through a secure channel in exactly the same way you get CA certs today, so this scheme is just as secure as SSL against an attacker who controls your entire connection. Sure, the scheme is only as good as your trusted source. But the trusted source could be very good. It could have multiple servers in different ISPs and even different countries verifying certs for you, and could use other methods of verification as well. The bank can easily check if their connections are getting MITM attacked. The hacker has to modify the certs seen by anyone who contacts the bank, even if he doesn't MITM every connection, and that would be easy for the bank to detect.
- kalmi10 16y ago
  You are getting out of scope. A hacker breaking into a bank's data center is not at all releated to the discussion at hand.