AnoNet
From Wikipedia, the free encyclopedia
- The correct title of this article is anoNet. The initial letter is shown capitalized due to technical restrictions.
anoNet is a decentralized friend-to-friend network, similar to Freenet in intent though not design. anoNet works by making it difficult to learn the identities of others on the network allowing them to anonymously host content and IPv4 services.
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[edit] Motivation
Implementing an anonymous network on a service by service basis has its drawbacks, and it is debatable if such work should be built at the application level. A simpler approach could be to design an IPv4/IPv6 network where its participants enjoyed strong anonymity. Doing so allows the use of any number of applications and services already written and available on the internet at large.
IPv4 networks do not preclude anonymity by design; it is only necessary to decouple the identity of the owner of an IP address from the address itself. Commercial internet connectivity and its need of billing records makes this impossible, but private IPv4 networks do not share that requirement. Assuming that a router administrator on such a metanet knows only information about the adjacent routers, standard routing protocols can take care of finding the proper path for a packet to take to reach its destination. All destinations further than one hop can for most people's threat models be considered anonymous. [citation needed]
[edit] Architecture
Since running fiber to distant hosts is prohibitively costly for the volunteer nature of such a network, the network uses off-the-shelf VPN software for both router to router, and router to user links. This offers other advantages as well, such as invulnerability to external eavesdropping and the lack of need for unusual software which might give notice to those interested in who is participating.
To avoid addressing conflict with the internet itself, the range 1.0.0.0/8 is used. This is to avoid conflicting with internal networks such as 10/8, 172.16/12 and 192.168/16, as well as assigned Internet ranges. In the event that 1.0.0.0/8 is assigned by IANA, anonet could move to the next unassigned /8, though such an event is unlikely, as 1.0.0.0/8 has been reserved since September 1981.
The network itself is not arranged in any regular, repeating pattern of routers, although redundant (>1) links are desired. This serves to make it more decentralized, reduces choke points, and the use of OSPF allows for more uniform traffic distribution. Work is underway to write a new routing protocol that would be purpose built for this kind of anonymous, ad-hoc networking.
Suitable VPN choices are available, if not numerous. Any robust IPsec package is acceptable, such as FreeSWAN or Greenbow. Non-IPsec solutions also exist, such as OpenVPN and SSH tunneling. There is no requirement for a homogeneous network; each link could in fact use a different VPN daemon.
[edit] Security
The list of organizations willing and/or capable of attacking such a network consists of the following.
- Stalkers who know their target in real life.
- Stalkers who only know their target on the metanet.
- Local law enforcement. Examples: County sheriffs, LAPD, NYPD, Metropolitan Police Service
- Regional law enforcement. Examples: New York State Police
- National law enforcement. Examples: FBI, RCMP
- Corporate entities. Examples: Sony's legal dept., MPAA, BSA, BayTSP, ALPA, BREIN
- Intelligence agencies. Examples: CIA, NSA, Mossad, MI6, DGSE
Type 1 attackers should have little or no knowledge that someone is present on anoNet, and often have better opportunity for attack in real life. Type 2 attackers should not pose a problem, assuming that users preserve their security.
Attackers which belong in types 3, 4 and 5 are seen as moderately worrisome. Even in the most liberal democratic nations, law enforcement authorities have been known to engage in privacy-breaching activities.
Type 6 attackers are perhaps the most dangerous adversaries given the threat model anoNet addresses. They have access to experts with considerable technical skills, and vast financial and legal resources.
Level 7 attackers are difficult to write about without speculating on their goals, resources or technical abilities. There are two schools of thought on this subject: the first ascribes to them nearly supernatural espionage talents which they use to great effect in their never ending schemes of global domination, and the second would describe them as moderately competent bureaucrats tasked with providing intelligence data on their enemies. How they would affect a metanet is largely dependent on which description is accurate, or to what degree both are.
[edit] Goals
One of the primary goals of anoNet is to protect its participants' rights of speech and expression, especially those that have come under attack of late. Some examples of what might be protected by anoNet include:
- Fan fiction
- DeCSS
- Criticisms of electronic voting machines.
- Bnetd and similar software
- Song of the South and other films of historical interest unavailable due to political controversy
[edit] How it works
It is impossible on the internet to communicate with another host without knowing its IP address. Thus, the anoNet realises that you will be known to your peer, along with the /30 subnet used for communicating with them. A routing protocol (OSPF) allows any node to advertise any routes they like, and this seemingly chaotic method is what provides users with anonymity. Once a node advertises a new route, it is hard for anyone else to determine if it is a route to another machine in another country via VPN, or just a dummy interface on that users machine.
It is possible that certain analysis could be used to determine if the subnet was remote (as in another country), or local (as in either a dummy interface, or a machine connected via Ethernet.) These include TCP timestamps, ping times, OS identification, user agents, and traffic analysis. Most of these are mitigatible through action on the users' part.
[edit] Scaling
Scaling is an issue with OSPF networks - generally they do not scale beyond 100 or 200 nodes. One solution for this is when the network reaches the limit, to start using another range within the main network, and link the two OSPF areas together with BGP.
[edit] Security concerns
One of the main concerns is that OSPF is a trusting routing protocol. Apart from an MD5 authentication key, there is not much security. Also, you can not filter the routes received by it. However, it is trivial to disconnect someone or block someone's OSPF packets if they are advertising large routes.
1.0.0.0 1.29.90.3 255.0.0.0 UG 20 0 0 tapsomenode
In this case, the route is being advertised from the node with address 1.29.90.3. A simple iptables rule to block traffic from that node would prevent the route from being propagated. If the node which connected to the host advertising the route dropped the VPN connection, this would restore the network to normal.
With the chaotic nature of random addressing, it is not necessary to hide link IP addresses. These are already known. If however, a user wants to run services, or participate in discussions anonymously, he can advertise a new route, and bind his services or clients to the new IP addresses.
