I'm really excited about this. Blossom is deceivingly simple, which is why it is powerful and why it has a chance of working.
What #nostr got right (and Bitcoin, for that matter) is that duplication is a feature, not a bug. "It takes advantage of the nature of information being easy to spread but hard to stifle," to quote Satoshi. De-duplication is a fools' errand, as it assumes a God's-eye-view. A global state is required to properly understand what to delete and what to keep. The second problem is of course indexing and discovery, which is indeed a hard problem if a global state is to be avoided. It's hard, but solvable. Especially if you already know what you're looking for, and especially especially if you have a common and purple-coloured discoverability layer.
Blossom is basically copying what nostr did for notes and applies it to arbitrary files. Instead of relays handling events, there's simple HTTP servers handling files. Like relays, servers are interchangeable as they share the same interface, encouraging duplication and redundancy. Instead of uploading something to a single server, you might upload it to five different servers. Popular and/or important files will be on many servers, which is how the online world works today already. Files that you need often might even be served by a #blossom server that is geographically close to you, just like we now have local cache relays packaged with some clients (or that you can self-host on your home server).
In the best case, Blossom will organically mirror what YouTube et al's content delivery networks already do well today, which is to provide file hosting that is high in availability and proximity. The neat thing about it all is that you can provide monetary incentives as it is nostr-native, and you get web-of-trust characteristics for free, as you can use only your servers, or those who are trusted by your friends, etc. And in the future, we'll probably have paid servers that whitelist npubs, just like we have paid relays now.
So why is all of that awesome? Well, here's the thing: as the user, you actually don't care where a file is hosted; you just care about the file itself. The current iteration of image (and other) hosts is incredibly stupid. Images are uploaded, downloaded, and re-uploaded without end, often with massive loss-of-quality as the same image is compressed and re-compressed a hundred times. It's always the same image, or at least it *should* be. With Blossom, it actually is.
Gone are the days of finding a thing and uploading again. You just need the hash, and the thing will appear. You could even insert images directly in notes with something like a blossom:ef1c26172f55017c9d9d6afa7cf22605b237b0fe92425e81e3b5e24d46c95448 and each client can choose how (HTTP, torrent, I2P, etc.) and where (public servers, private servers, etc.) to retrieve it from.
But wait, there's more. Remember the monetary incentives we talked about? It is what allows for the emergence of a proverbial "assassination market" for files: you provide the hash, along with a bounty of 21k sats to anyone who can provide the file most readily. Servers could provide cryptographic proof that they have the file, and you could escrow the money until delivery is done and you verify the file on your side. The building blocks are already there, we just need to put them together in the right way.
Blossom is one of the most exciting projects that came out of the first nostr:npub1s0veng2gvfwr62acrxhnqexq76sj6ldg3a5t935jy8e6w3shr5vsnwrmq5 cohort, aka #SEC-01. I'll have more to say about all the other amazing #SovEng projects that came out of the discussions and collaborations we had, but now I'll have to go and upload some files.
