Spread of Tor nodes in Greece
So where can Tor nodes be set up? Since we need bandwidth, home servers or our personal computers are excluded. Home VDSL connections may offer a better level of service than aDSL, but there is still the issue of increased latency when the line is “full” as well as the cost of running a server 24/7 inside a home. Broadband in Greece is (still) far from that point.
A very good suggestion for setting up Tor nodes are universities. In fact, Tor has attracted the interest of the international scientific/academic community for several years, which conducts significant research on Tor (for example, at MIT, Waterloo, Cambridge, Minnesota, Karlstad, Carnegie Mellon ), while some institutions abroad also operate Tor (exit) nodes. This means that not only can the previously unused bandwidth of Greek universities be utilized - several of them are connected to 10Gbps lines while using less than 300 to 500Mbps - but students and academics can also conduct research on the Tor network, as is done in several universities around the world.
Here, of course, one can observe that all universities in Greece use GRNET as an upstream ISP (in other words, GRNET provides internet to all Greek universities), which is correct, but many of the universities have their own AS, their own IP range and we are certainly talking about different “datacenters” as well as different administrators. So many of the “requirements” for variety are satisfied. Since in Greece the purchase of bandwidth within Greek datacenters (Lamda Helix, Med Nautilus, Forthnet, OTE, etc.) is still quite expensive, it is not easy to set up Tor nodes in them so that other ISPs besides GRNET can be used. Those who have access to such datacenters, and get network from other Greek or foreign ISPs, can see the paragraph on Tor Bridges below.
Setting up non-exit, simple relay, nodes is actually completely safe for the administrators. Since no traffic ever leaves these nodes to the Internet, there is never any legal issue. To be useful, a relay node for Tor should have at least 10MBps bandwidth and operate 24/7. Following the recent court decision acquitting a Tor exit node administrator in Greece [8], it seems that the way is open for even exit nodes to be set up without legal problems.
To set up a relay, you only need to install Tor. On a Debian/Ubuntu:
$ sudo apt-get install tor
for installing the packages it is recommended to add the Tor Project repositories, as shown in the link above)
A torrc for a non-exit relay could be the following:
SocksPort 0
ORPort
RelayBandwidthBurst 2 MB
ExitPolicy reject *:*
If the line “ExitPolicy reject *:*” is removed then the relay is converted to exit with the following default exit policy:
reject *:25
reject *:119
reject *:135-139
reject *:445
reject *:563
reject *:1214
reject *:4661-4666
reject *:6346-6429
reject *:6699
reject *:6881-6999
accept *:*
optionally, contact information for the relay node administrator can be entered in torrc
Nickname
Contact Info
Tor Bridges
When Tor clients want to use the Tor network, they download a list (consensus) of all the public relays on the network, and begin creating virtual paths to Tor. This list is publicly available to everyone, including those who want to block access to the Tor network, such as China or a corporate network.
Tor Bridges are simple Tor nodes that are not listed in the public list (consensus) of relays. Bridges were created as a countermeasure to the blocking of Tor on specific networks. Users on such networks cannot connect to Tor, but can connect to bridges. Bridges act as bridges between the blocked user and the rest of the Tor network.
Tor Bridges are just as important as regular Tor nodes, as they help users who are on networks with extreme restrictions. Since these bridge nodes do not serve as many users as public relays, they have lower bandwidth requirements. If you have a computer to spare and do not have high bandwidth, you can turn it into a Tor bridge. In fact, with the addition of Pluggable Transports (obfs3, scramblesuit, etc.), Tor bridges have become more useful than ever, as they now offer the ability for a Tor user to hide even the very use of the protocol/program. In other words, someone watching the user connect to a bridge with obfuscation support (pluggable transports), it is impossible to distinguish that the traffic is Tor.
Setting up a bridge is also simple. On a Debian/Ubuntu machine, all you need to do is:
$ sudo apt-get install tor obfsproxy
A typical torrc for a bridge is actually very simple:
SocksPort 0
ORPort c
BridgeRelay 1
PublishServerDescriptor 1
ExitPolicy reject *:*
ServerTransportPlugin obfs3,scramblesuit exec /usr/bin/obfsproxy managed
Similarly to relay nodes, the administrator's contact information can also be optionally entered here.
More technical details
With the above instructions we aim to show that setting up such nodes is not something technically impossible. Of course it is a brief description, and for more details or questions you can refer to torproject.org, the relevant email lists , or the #tor channel on the OFTC IRC network. Finally, you can also contact contact [duck] skytal.es
In conclusion
In Greece, there is the possibility and necessity to contribute more to the Tor network. The technical aspect of setting up nodes for the Tor network is passable. In the legal aspect (which concerns only exit nodes) there is only one historical precedent, where the court decision was very positive for the node administrator. The smooth operation of exit nodes in Greece will only result from a continuous effort to communicate with every interested or involved entity, the way in which Tor operates. It is necessary to make known in advance what Tor is, why we support it, how a node operates, etc. Finally, the academic community has the material and potential, both for the operation of Tor exit nodes and for conducting research on Tor or in general issues of anonymity and privacy.
Source: skytal.es
