This table lists often-used terminology when discussing I2P and cryptography.
  • I2P: Invisible Internet Project: a project meant to provide an anonymity layer, so user can communicate anonymously using a range of applications.
  • Router: The core I2P software, which routes encrypted packets on the I2P network. All routers by default participate in the network, which both helps the network and provides cover traffic for any clients or servers connecting to the I2P network through the router.
  • RouterIdentity: A collection of information required to communicate directly with a router, such as its IP address and listening port, public signing and encryption keys etc.
  • Tunnel: An anonymous communication pathway between a client or server and the I2P network. Tunnels are unidirectional, so any one client or server must have at least two Tunnels - one for inbound traffic and one for outbound traffic.
  • Destination: The cryptographic identity of a tunnel. These are the identities of clients and servers within the I2P network, and are analogous to the IP:port of a computer on the normal internet.
  • LeaseSet: A collection of information required to communicate with a client or server at a particular Destination, such as the gateways of the inbound Tunnels for that Destination.
This table lists definition of different networks and their components. These terms and the definitions provided are taken from Decentralization Off The Shelf: 7 Maxims by Simply Secure(used with permission).
  • Decentralization: Network architecture that avoids reliance on a single party. Encompasses peer-to-peer, blockchain, federated, and distributed technologies that involve many individual users.
  • Peer-to-Peer (p2p): Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Popularized by BitTorrent, Napster, and Bitcoin.
  • Federated: Federation allows separate deployments of a service to communicate with each other through a common protocol, for instance a mail server run by Google federates with a mail server run by Microsoft when you send an email from to Each deployment may host multiple users.
  • Blockchain: A distributed ledger that can record transactions between multiple parties efficiently and in a verifiable and permanent way.
  • Distributed systems: Academic topic within the discipline of Computer Science which is concerned with the design of computer systems that consist of many individual computers connected over a network. Peer-to-peer networks and blockchains are examples of distributed systems architectures.
  • TCP/UDP: The two foundational transport protocols used on the Internet. Common protocols used to send data between two computers.
  • DHT: Distributed hash table, used in some projects to connect peers to each other by storing information in the form of key-value pairs in a distributed manner.
  • IP address: A number of a computer or network which is unique and thus can be used to address it.
  • WebRTC: A protocol standard for establishing connections in a web browser where data passes directly between users.
  • Hash: A number, usually displayed as a string of letters and numbers. It can serve as a ‘fingerprint’ uniquely identifying data.
  • UX: User experience, the overall experience of a person using a product or a service, especially in terms of how easy it is to use.