The paper identifies and demonstrates the existence of a covert sublayer, called the Exclusive Network, within the I2P anonymous network, which allows nodes to host services without being discoverable via the network's public database.
Abstract
More Like ThisThe Invisible Internet Project (I2P) is a peer-to-peer anonymous overlay network whose architecture includes a structurally distinct sublayer not characterized in existing security literature. We term this sublayer the Exclusive Network: nodes here host operational services and draw on I2P's routing resources, but publish no RouterInfo record to the network's distributed database (NetDB). In a controlled three-node testbed, we demonstrate that an Exclusive Network node survives sequential floodfill queries from a pool of routers with zero NetDB hits, while its hosted service remains continuously accessible to authorized peers. This property is exploitable by documented I2P-based malware, for example, I2PRAT (RATatouille), for persistent command-and-control operations against national assets or corporate networks. The structure is analogous to nation-state Operational Relay Box (ORB) infrastructure. The existence of this sublayer, together with the inability of top-down empirical mapping to characterize it, motivates a move toward formal analytical methods to understand the emergence and behavior of covert networks within I2P.