When you request a piece of content on the Web, you supply your browser with a URL, which is information that can be used to locate the resource you’re looking for. That location process is remarkably physical. A Web URL usually has a domain name, which can be resolved to an IP address, which is ultimately used to make a connection between your browser and a specific server somewhere in the world. Your browser then supplies that server with the filename of the piece of content you seek, and the server responds with the content.

IPFS works differently. Instead of identifying content using the location and filename, the system identifies content using a cryptographic hash of the content itself. To fetch content, you connect to a peer-to-peer swarm and ask if anyone has the content that matches a specific hash. This hash is a tamper-proof digital fingerprint. It’s a 256-bit number that nearly uniquely identifies each piece of content.¹

It may be that nobody has the content that matches the hash you are looking for other than the original publisher. In that case, you will ultimately connect to the publisher’s computer, which may be located on the other side of the globe, with all the speed-of-light-driven latency that implies. But on the other hand, someone closer to you may have a copy of the content and may be the first to respond to your request. Because cryptographic hashes are tamper-proof, you can download the copy from your neighbor and know with certainty that it is the same content you were requesting. Your system recalculates the hash of the content automatically to verify that it matches what you asked for.

The benefit of this content-based addressing is even more stark if we consider its use on a nascent Mars colony. Imagine a colonist trying to connect to servers on Earth, with one-way latencies of between 4 and 24 minutes, depending on the planets’ relative orbital positions. Each round-trip request, therefore, takes between 8 to 48 minutes. With that kind of delay, it makes sense to cache everything you get back from Earth. That way, if another colonist wants the same content, they can get it locally without going through another interplanetary request, neatly sidestepping the speed-of-light problem. Indeed, this use case is what inspired IPFS’s name—Inter-Planetary File System.

But as the failure of the existing Web to disempower territorial governments demonstrates, you don’t have to be on Mars to benefit from content-based addressing. If IPFS were widely adopted, it would become possible for a single jurisdiction to become a data haven able to serve the globe—and indeed the solar system—at low latency. Alternatively, servers in orbit could be seeders of uncensored content on the IPFS network. The structure of the IPFS network decentralizes content distribution so that people who want to serve a global audience need not actually have a physical presence in multiple jurisdictions, at least not for the purpose of literally serving static files.