Our Promise

We know that every complex system can be broken, Gate17 is no different. We do the best we can and we think we’re doing quite good. Nevertheless we have to set limits to what extent we can and to which lengths we will go to protect you. Here we want to clearly communicate these limits:

Money
If you throw enough money at something long enough, it will eventually crumble. In our case we estimate how much an attack on Gate17 costs and set a limit to what extent we promise to intervene. For now this limit is set at one million EUR (Q3 2018) - we will periodically review and update this value. Be assured that if there is a feasible solution, we will always react to a threat as fast as we can. Let’s look at an example of how attack costs are estimated: If an attack requires 100 server to be run for 3 months and requires a month worth of work, we can estimate that this attack would cost about 19000€ (100 * 3 * 30€ + 10000€).

Legal
We will not break any laws. Our systems are designed to collect as little personal information as possible and we continually evaluate concepts to further decentralize our control over the Gate17 network. Should we ever be forced to break the system or collect data on you, Safing (the company) will hara-kiri.

Privacy

To protect your privacy, we use a double ratchet based protocol to provide perfect forward and backward secrecy. Used algorithms can be easily changed to address new threats and trust issues. If you want to dig deeper, check out our crypto libarary: Tinker

Your private data is perfectly safe within Gate17.

Anonymity

In order to anonymize connections, they are routed through multiple network nodes, encrypting/decrypting your data at every node. This proven method, known as onion-routing, is the state-of-the-art for anonymity networks - which has well known weaknesses.

There are three possible attacks to break this anonymity:

Rogue Nodes

The obvious threat to anonymity are nodes that are compromised or silently collude. These nodes then extract session data and if a route is chosen that consists entirely of such nodes, the attacker can link the source to the destination.

The best way to tackle this problem is have a great community which hosts a lot of nodes. Node owners are encouraged to mark their nodes as a group. Clients will then aim to diversify node ownership when calculating routes through the network.

At least for the first phase of operation, we will have to ability to moderate community nodes so that we can blacklist nodes that do not act in the interest of the community. We are looking into options how to decentralize this control over the network.

Traffic Analysis

One major concern with all anonymity networks is traffic analysis. With enough network visibility, one can easily find out where a connection really goes to and comes from, without even interacting with the network itself.

To provide the best possible anonymity, we studied the principles of anti traffic analysis described by Gordon Welchman in his book The Hut Six Story.

Here we compare these principles with Gate17.

# Principle Gate17
1 All nodes are full nodes of the network with multiple connections (no leaf nodes). With the exception of clients, all nodes in the network are full nodes.
2 Connections have link layer encryption. True.
3 Communication is end-to-end encrypted. True.
4 All nodes store and forward (the longer stored the better) Not really, as it’d be a pain to use. Will implement if there is demand.
5 Connections have a fixed bandwidth, which is padded to full utilization at all times. Kind of: Network packets are fixed, but bandwidth is not. Will implement if there is demand.

In our current state, we fulfill three out of these five principles on average. The last two put a heavy load on the network and make it a lot slower. We think that Gate17 is designed to withstand traffic analysis to a great amount. Should things change or the need arise, we will further adopt these principles.

If there is enough demand, we will also implement the last two principles in a hybrid form, so you can opt-in if you need the extra protection.

The traffic analysis method is feared because it can be executed passively, which makes it really hard to detect.

Data Leaks

Not so obvious, but very dangerous attacks on the anonymity in the network are data leaks. As these happened so often with other networks in the past, we made sure we could address these optimally.

  1. Gate17 does not forward layer 4 network data, so no data can leak from that layer into the Gate17 network and beyond.
  2. In case of a crash, connections are not automatically rerouted over the open Internet, but are terminated.
  3. Other data leaks are more complex to address and are - to some extent - a cat-and-mouse game:
    • WebRTC uses STUN/TURN servers to find your network location. Portmaster will block / answer these requests.

Please note that this is about data leaks of networking (meta)data. Gate17 cannot protect you from sharing your data or using applications that make you easily identifiable, like your browser, if not configured correctly.