Privacy
If you are wondering how good the privacy really is, let me warn you: Do not trust it! If you are looking for serious privacy, use Tor. It is not perfect either, but *much* better. If you do, read the manual carefully. It explanins how to configure programs so that they do not leak personal information.
What cor tries to achieve is not the same as Tor. Tor has the sole purpose of creating a network for people needing privacy. Cor tries to be a way for building zero configuration networks. While privacy is important here as well, it is not possible to build anything nearly is good as Tor under the constraints cor is facing. However, I still have not seen anybody else even trying to build a layer 3 with privacy in mind. The trend is exactly the opposite: There is more and more data retention and other stuff. Privacy also needs to be something which can be default enabled. Having only something which can only be used for special purposes, because it is slow will probably not be enough.
If you are interested in a list of things, which decreases privacy in the cor network, here it is:
- Sniffing wireless networks and installing a large number of active routers is way easier for attackers than doing the some in the internet. Even if data is reencrypted at each router, it is still possible to identify individual streams via timing attacks. Protecting against them is very hard.
- The credit system way also provide hints for doing traffic analysis.
- Route selection is not completely random, like it is in TOR. Cor tries to find a short route to the target. It would be possible to change this to include some randomness by changing the clients and leaving the routers in the middle alone. However, the effect this will have on privacy is hard to tell.
- A network has to be big in order to provide good privacy. Cor networks will often be very small. Even if a cor network is big, the routing daemon will select internet uplinks in the neighborhood. In most cases having the IP address of the uplink will probably mean that the number of suspects is down to fewer than 100.
- Privacy will depend a lot on configuration. Whether the tor-like reencryption is enabled for all rousters is up to the configuration. In some cases users may want to skip this step for some or all routers. This can reduce encryption to end to end or even plaintext. Every user can configure this in the routing client. There are also some things which to be configured on the routers. This includes the allowed algorithms and whether encryption is support at all. I do not think encryption will be disabled on many routers, if it is implemented in a way which does not slow down users not using this. But even few encryptionless routers can make things difficult.
- In some cases users might use cor as their only internet connection. This increases the danger of one program sending personal data and another data, which should not be linked your personal data, over the same connection to the same internet uplink. Tor has this problem as well, but to a lesser extend. Programs sending personal data will rarely be configured to use Tor.
- Your services are not hidden. Finding your approximate location is only a matter of knowing the locations of a few hosts around you. Finding your exact location is only a matter of walking with an antenna and seeing where the signal gets stronger.
- The location of mobile nodes is not hidden either. An attacker who has a single node anywhere in the network can track their movements easily.
- Cor has received anything a *lot* less review than other privacy networks. The consent for privacy networks seems to be that it is *very* hard to get right and even the best networks are everything but perfect.