In this article, we will explore the inner workings of IPFS (InterPlanetary File System). We’ll delve into the major subsystems that make up IPFS and how they function to revolutionize data storage and distribution.
Subsystems Overview
IPFS consists of several subsystems that work together to represent, address, route, and transfer data. Let’s take a closer look at each of these subsystems:
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Representing and Organizing Data:
- CIDs, IPLD, UnixFS, MFS, DAG-CBOR, DAG-JSON, CAR files
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Content Routing and Linking:
- Kademlia DHT, Delegated routing over HTTP, Bitswap, mDNS
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Transferring Data:
- Bitswap, HTTP Gateways, Sneakernet, Graphsync, more in development
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Addressing for Data and Peers:
- Multiformats
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Bridging Between IPFS and HTTP:
- IPFS Gateways, Pinning API Spec
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Peer-to-Peer Connectivity:
- libp2p (TCP, QUIC, WebRTC, WebTransport)
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Mutability and Dynamic Naming:
- IPNS (Interplanetary Naming System), DNSLink
How IPFS Represents and Addresses Data
IPFS represents data using content-addressed blocks, ensuring secure and efficient data storage. The following subsystems enable IPFS to achieve this:
Content Identifier (CID)
IPFS uses a unique identifier called a Content Identifier (CID) to address data. CIDs are generated by combining the data’s hash with its codec. This approach allows data to be fetched based on its content rather than its location. The CID also enables verification, as the received data’s CID can be compared to the requested CID.
InterPlanetary Linked Data (IPLD)
IPLD is a crucial component of IPFS responsible for representing and addressing content-addressed data. It utilizes a directed acyclic graph (DAG) called a Merkle DAG to establish relationships between data. One specific implementation of IPLD called UnixFS allows IPFS to handle files, directories, and symlinks. IPLD offers flexibility, interoperability, and backwards compatibility.
Content Addressable aRchive (CAR) Files
IPFS employs CAR files to store and transfer serialized archives of IPLD content-addressed data. These files function similarly to TAR files and are designed to store collections of content-addressed data.
How Content Routing Works in IPFS
Content routing is vital for IPFS to locate and retrieve data. IPFS utilizes the following subsystems to determine where to find specific content:
Kademlia Distributed Hash Table (DHT)
IPFS uses Kademlia, a decentralized DHT, to find peers in the network storing the requested data. Kademlia maintains a distributed table across multiple nodes, storing information about which peers have which data. This self-organizing system efficiently handles node churn and relies on libp2p for connectivity.
Bitswap
Bitswap is a message-based, peer-to-peer network protocol used for both content routing and data transfer. IPFS nodes can ask their connected peers for specific content without relying on the Kademlia DHT. Peers store wantlists, enabling them to fulfill requests from other nodes.
Delegated Routing over HTTP
Delegated routing allows IPFS implementations to offload content routing to another process/server using an HTTP API. This mechanism provides flexibility when nodes lack computing resources or utilize custom routing backends.
mDNS
To discover peers within local networks efficiently, IPFS employs Multicast Domain Name System (mDNS). This DNS protocol resolves domain names to IP names without requiring a name server. mDNS enables IPFS nodes to discover peers without coordination or internet connectivity.
How IPFS Transfers Data
In addition to routing data, IPFS needs to distribute and deliver content-addressed data efficiently. The following subsystems handle data transfer within the IPFS network:
Bitswap (for Data Transfer)
Bitswap, as mentioned earlier, not only aids in content routing but also facilitates the transfer of data. Connected peers can directly transfer requested blocks to IPFS nodes without traversing the Kademlia DHT. Peers store wantlists, ensuring that the requested data can be transferred to the original requester when available.
IPFS HTTP Gateways
HTTP Gateways provide an interface for applications that do not fully implement IPFS subsystems. They allow these applications to fetch data from the IPFS network using an HTTP interface.
Sneakernet
In situations where network connectivity is not possible, IPFS supports the use of “sneakernet” to transfer content-addressed data between nodes. Sneakernet involves physically transferring CAR files between network drives. IPFS ensures the data’s integrity and verifiability, even in an air-gapped environment.
FAQs
Q: What is IPFS?
A: IPFS, short for InterPlanetary File System, is a decentralized file storage and distribution system that addresses files based on their content rather than their location. It offers secure, efficient, and resilient data storage and transfer.
Q: How does IPFS ensure data integrity?
A: IPFS uses content addressing and cryptographic hashes to ensure data integrity. Each file is assigned a unique Content Identifier (CID) derived from its content. When retrieving data, IPFS verifies that the received data matches the requested CID.
Q: Can IPFS be used for large-scale data distribution?
A: Yes, IPFS is designed for large-scale data distribution. Its decentralized nature allows for efficient content routing and transfer, making it suitable for distributing large amounts of data across a network.
Conclusion
IPFS revolutionizes data storage and distribution by employing various subsystems that work together seamlessly. From representing and addressing data to content routing and data transfer, IPFS offers a decentralized, efficient, and secure solution for the future of the internet.
For more information on IPFS, visit Virtual Tech Vision.
