Interledger

The Interledger network connects financial services that have implemented the Interledger Protocol (ILP) and helps make payments easier, faster and cheaper. 

Traditional payment networks operate independently from each other. Sending money is easy only if the sender and recipient have accounts on the same network, but it can be slow and expensive if they have accounts on different networks.

Interledger makes it easy and inexpensive to send payments in whatever currency or payment network you choose, because Interledger is not tied to any one company, payment network, or currency. Using Interledger, you can send Australian Dollars to someone who wants to receive British Pounds, or you can send United States Dollars to someone who wants to receive Euros.

Built on modern technologies, Interledger can handle up to 1 million transactions per second per participant. The reduced cost of transactions, and increased throughput when compared to traditional payment networks, allows Interledger-enabled financial services to explore new use-cases currently impossible in traditional financial systems. 

Micro transactions, as low as the 100th part of a cent, streaming payments and currency exchange during network traversal are all-new use-cases enabled by implementing the Interledger Protocol and joining the Interledger network.

The Interledger Protocol (ILP) grew out of a need to solve complexity within the field of global payments. It’s an open, neutral protocol for transferring money based on TCP/IP, the protocol that defines the Internet. It was designed for sending packets of money across different accounting ledgers, at the speed of the internet.

The latest version of ILP (ILPv4) defines a set of rules that describes how ledgers should connect and communicate over the Interledger network. ILPv4 is a simplification of previous versions of the protocol that is optimized for routing large volumes of low-value packets, also known as "penny switching".

ILPv4 can be integrated with any type of ledger, including those not built for interoperability, and it is designed to be used with a variety of higher-level protocols, like Open Payments, that implement features ranging from quoting to sending larger amounts of value with chunked payments and delegated access into accounts.

Like the internet, connectors route packets of money across inter-connected nodes.  ILPv4 is a request/response protocol, where requests and responses are ILPv4 packets. Typically, a single aggregate payment from sender to receiver is split into multiple ILP packets. Each ILP packet contains transaction information, which is private to the ledgers participating in the transaction.

The open architecture and minimal protocol enable interoperability for any digital financial service.

Interledger enables secure, multi-hop payments using Hashed Timelock Agreements. As of ILPv4, these conditions are not enforced by the ledger, as it would be too costly and slow. Instead, participants in the network use these hashlocks to perform accounting with their connected nodes. 

Accounting is used to determine in-flight balances, which are periodically settled. Because the Settlement phase is completely outside the Interledger Protocol, it enables ILP to have much faster messaging and clearing of a payment than any traditional financial system.