I2P Garlic Tunnel Security: A 2D Network Model

What Garlic Tunnels Are

Garlic routing is a technique used in the I2P network to enhance privacy by encrypting messages into multiple layers of encryption. Each layer contains part of the destination address, allowing data to be decrypted hop-by-hop without revealing the full path until it reaches its final destination.

In the context of I2P's 2D model, each router in a ring is connected to several other routers, forming a network where messages are sent through a series of hops. Each hop decrypts part of the message and adds another layer of encryption before passing it on.

How Garlic Tunnels Work

The process begins with a client generating a random set of hops, each representing a router in the network. These hops are then used to build an outbound tunnel from the client to the destination. Simultaneously, an inbound tunnel is built from the destination back to the client, ensuring that both ends can communicate securely.

The security of this system relies on the randomness and length of these tunnels, as well as the number of hops involved. Each additional hop increases the complexity of tracking a message's path, making it harder for adversaries to deanonymize users.

Security Parameters

In the I2P 2D model, several parameters can be adjusted to study their impact on security. The tunnel length determines how many hops a message must traverse before reaching its destination. A longer tunnel means more encryption layers and thus greater resistance against adversaries.

The size of the tunnel pool affects the number of possible paths through which messages can travel. Larger pools reduce the likelihood that an adversary can predict or intercept specific tunnels, thereby enhancing overall security.

Adversary Influence

In the model, adversaries are represented by a certain percentage of routers in the network. Their presence and strategic placement can significantly impact the risk of deanonymization. By adjusting this parameter, one can observe how different levels of adversary control affect tunnel security.

The risk-history chart tracks the evolution of deanonymization risk over time as new tunnels are built. This visualization helps understand how various factors—such as tunnel length and pool size—affect long-term security.

Frequently asked questions

Try it live

Everything above runs in your browser — open I2P Garlic Tunnel Security Simulator (2D) and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.