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> You can't separate encryption from authentication Why not? So you are saying these are our only 2 options? 1. I don't know who you are so we can't encrypt

> You can't separate encryption from authentication Why not? So you are saying these are our only 2 options? 1. I don't know who you are so we can't encrypt our conversation. 2. I know who you are so we can encrypt our conversation. Why is there not a third option? 3. I don't know who you are but we can still encrypt our conversation.

icebraining 12y ago
You can, it's just that you don't know if the connection is actually encrypted from you to the person/machine you're talking to, or if there's someone in the middle silently spying on you and relaying the messages between the two. And by "someone," that doesn't necessarily mean an actual person specifically targeting you, it may just be an infected machine or router that snoops on everyone.
snowwrestler 12y ago
There is option 3, for example with a self-signed certificate. That works well for talking to your own server. But if you're trying to reach some other site, how would you know if someone is pretending to be the site you're trying to reach? Encryption is not much use in protecting privacy, if your encrypted connection goes to an imposter. That's why authentication matters as much as encryption for surfing the web.
- foundart 12y ago
  I wouldn't. But if I'm using an unencrypted connection I know for sure that everything is readable all along the way. It seems to me that implicit in the argument against option 3 is the assumption that if we have a system in which encryption is not tied to authentication that the net will be filled with MITM attackers, thus effectively rendering option 3 identical to option 1. Is that a valid assumption?
  - snowwrestler 12y ago
    Yes. With modern tools MITM is akin to spam: almost no marginal cost, so even if it only hooks a few people, it's worth trying. Here are some examples: http://arstechnica.com/tech-policy/2013/04/how-a-banner-ad-for-hs-ok/ http://arstechnica.com/tech-policy/2013/04/how-a-banner-ad-f... http://gizmodo.com/gogo-is-using-man-in-the-middle-malware-tactics-on-its-1677559652 http://gizmodo.com/gogo-is-using-man-in-the-middle-malware-t... Keep in mind these are legitimate, professional ISPs doing this, so we're not even into criminal or state-level MITM attempts, let alone basic griefing tools like Firesheep. So yes, it is a valid assumption that the net is filled with MITM attackers.

icebraining 12y ago

You can, it's just that you don't know if the connection is actually encrypted from you to the person/machine you're talking to, or if there's someone in the middle silently spying on you and relaying the messages between the two. And by "someone," that doesn't necessarily mean an actual person specifically targeting you, it may just be an infected machine or router that snoops on everyone.

snowwrestler 12y ago

There is option 3, for example with a self-signed certificate. That works well for talking to your own server. But if you're trying to reach some other site, how would you know if someone is pretending to be the site you're trying to reach? Encryption is not much use in protecting privacy, if your encrypted connection goes to an imposter. That's why authentication matters as much as encryption for surfing the web.

foundart 12y ago
I wouldn't. But if I'm using an unencrypted connection I know for sure that everything is readable all along the way. It seems to me that implicit in the argument against option 3 is the assumption that if we have a system in which encryption is not tied to authentication that the net will be filled with MITM attackers, thus effectively rendering option 3 identical to option 1. Is that a valid assumption?
- snowwrestler 12y ago
  Yes. With modern tools MITM is akin to spam: almost no marginal cost, so even if it only hooks a few people, it's worth trying. Here are some examples: http://arstechnica.com/tech-policy/2013/04/how-a-banner-ad-for-hs-ok/ http://arstechnica.com/tech-policy/2013/04/how-a-banner-ad-f... http://gizmodo.com/gogo-is-using-man-in-the-middle-malware-tactics-on-its-1677559652 http://gizmodo.com/gogo-is-using-man-in-the-middle-malware-t... Keep in mind these are legitimate, professional ISPs doing this, so we're not even into criminal or state-level MITM attempts, let alone basic griefing tools like Firesheep. So yes, it is a valid assumption that the net is filled with MITM attackers.