4 ms·

Through the two major DNS privacy talks on FOSDEM I felt a bit at odd that so much effort is being put into the idea that giving all information to google will

by belorn 8y ago

Through the two major DNS privacy talks on FOSDEM I felt a bit at odd that so much effort is being put into the idea that giving all information to google will give best privacy. In basic security theory we talk about assets that need to be defended, and attackers we need to defend against. Why give everything to a company which revenue is based on breaking privacy? It sound completely incompatible with the idea of privacy. Running your own resolver will give the authoritative servers the ip address of the request, but does this leak any assets to any potential attacker? The owner behind the authoritative servers already get the web logs so what additional information is being leaked. It seems to me that in order to get higher level of privacy you would need to run a VPN or Tor, in which case the DNS traffic can just go through the same path.

zzzcpan 8y ago
It's worse than that: you already have to trust your ISP, but with third party DNS resolver you not only have to trust your ISP, but also another third party. Encrypted SNI is another sneaky proposal that claims it can help with that, but cannot actually. Even in the ideal case when everyone is using ESNI, there is still a lot of information that you have to trust your ISP with, like access patterns, IP addresses, response sizes, etc. and on top of that trust an extra third party with DNS. Basically it's all awful and ill-advised form security and privacy perspective, you always need at least a VPN if you can't trust your ISP. DoH can only make it worse.
_null_ 8y ago
>Running your own resolver will give the authoritative servers the ip address of the request, but does this leak any assets to any potential attacker? The owner behind the authoritative servers already get the web logs so what additional information is being leaked. This is addressed in the panel. The argument is that there is some "privacy mixing" because owner of the authoritative server only sees a highly-trafficked resolver as the source, and not your home network resolver.
- belorn 8y ago
  Yes, the authoritative server get less data from the DNS server but the owner of the domain already get the information from web server logs and similar sources. I do not see how dns mixing provide any privacy in any common threat model. In the first case a client that request a webpage contact company X authoritative server with private information [IP ADDRESS], creating a record on the DNS server, and then visit company X web server creating a second record at the same company with the same [IP ADDRESS]. In the second case a client request a webpage of company X by contacting google, creating a record on google DNS server with [IP ADDRESS], and then visits company X and create a record there with [IP ADDRESS]. In one case one company has the data, and in the second case two companies has the data. It does not make any sense.

by belorn 8y ago

zzzcpan 8y ago

It's worse than that: you already have to trust your ISP, but with third party DNS resolver you not only have to trust your ISP, but also another third party. Encrypted SNI is another sneaky proposal that claims it can help with that, but cannot actually. Even in the ideal case when everyone is using ESNI, there is still a lot of information that you have to trust your ISP with, like access patterns, IP addresses, response sizes, etc. and on top of that trust an extra third party with DNS. Basically it's all awful and ill-advised form security and privacy perspective, you always need at least a VPN if you can't trust your ISP. DoH can only make it worse.

_null_ 8y ago

>Running your own resolver will give the authoritative servers the ip address of the request, but does this leak any assets to any potential attacker? The owner behind the authoritative servers already get the web logs so what additional information is being leaked. This is addressed in the panel. The argument is that there is some "privacy mixing" because owner of the authoritative server only sees a highly-trafficked resolver as the source, and not your home network resolver.

belorn 8y ago
Yes, the authoritative server get less data from the DNS server but the owner of the domain already get the information from web server logs and similar sources. I do not see how dns mixing provide any privacy in any common threat model. In the first case a client that request a webpage contact company X authoritative server with private information [IP ADDRESS], creating a record on the DNS server, and then visit company X web server creating a second record at the same company with the same [IP ADDRESS]. In the second case a client request a webpage of company X by contacting google, creating a record on google DNS server with [IP ADDRESS], and then visits company X and create a record there with [IP ADDRESS]. In one case one company has the data, and in the second case two companies has the data. It does not make any sense.