service discovery on ipfs

[whyrusleeping]

The question of service discovery on ipfs has been asked a few times, so I figured I would write out my thoughts on the matter.

Ipfs has a built in mechanism for nodes to advertise that they have a certain chunk of data, this mechanism is called "Providers". It is as simple as telling the routing system "I Provide block X". And requests may be made of the routing system for providers of block X. We can slightly abuse this to have a way for peers running certain services to find eachother easily. By crafting a block unique to the service (I'll refer to this as the "Identification block"), and having all peers running the service "Provide" the block, finding peers running a given service is as easy as requesting providers for that services identification block.

[pjz]

To translate this into something a bit more concrete, you can do this today by doing:

Pick a nonce, something to be prepend to your service names ; this essentially defines your network. If someone else knows this nonce they'll be able to spoof and/or read the state of your service availability.

Publish service availability by publishing a block consisting of { nonce + service name }. In other
words, echo $NONCE$SERVICE_NAME | ipfs block put

Finding a service by doing ipfs dht findprovs $BLOCKNAME. Since it's a raw block, $BLOCKNAME can be computed from $NONCE$SERVICE_NAME using a multihash implementation.

[whyrusleeping]

to create a 'raw block' with the data you want, you need to use echo $NONE$SERVICE_NAME | ipfs block put.

Also, anyone who knows your $BLOCKNAME will be able to get the block and 'spoof' it, so theres really no need for the nonce, its not really doing anything for you.

[pjz]

oh, good point wrt $BLOCKNAME ; I was thinking of them being able to spoof alternative services.

And yup, ipfs block put instead of add - that's what I get for trying to go from memory.

[pjz]

So: Is there a way to do service discovery without being spoofable?

[whyrusleeping]

Well, not in a decentralized manner. If you want a single node to control service discovery you could have peers register with the 'master' node and have it build a list for peers to use.

[hackergrrl]

You could avoid spoofing by including a public key with the service name in the block, and then sign all traffic from that service with it.

[dimitarvp]

TL;DR of the issue I linked from: Paid pin services are a worrying sign. IMO we have enough centralization already; if we let corporate entities manage most of IPFS' replication/redudancy for money, then what's the point of even having IPFS? We need to step up and not allow it to turn into a WWW copy.

I feel the mechanism outlined here can be used in the scenario of people/organizations willing to donate bandwidth and storage and hopefully eliminate the need for paid pin services. Plus, I don't think encryption would be needed. We can devise a specifically crafted block which states exactly "I am a traffic and storage donator". Nothing secret or needing spoof protection here I think.

The part I can't figure out yet (being a total novice in IPFS) is how to also state "I can offer up to 3MB/s upload and 6MB/s download, and I am willing to donate 150GB of space, of which 107GB are free right now". Is there a way to provide such an additional information to somebody after they discover me via the above technique?