Not exactly. That scheme has the work verification happen at the clients, allowing a filtering by users for what has sufficient work. I'm not all that excited about that kind of scheme. The relays need the help with spam, not the clients, if we're going to avoid the mistakes of SMTP.
There are a few. I think Amethyst on android has channels.
https://garnet.nostrian.net/ is the one I've played with a bit.
#[0]
Saving this for later.
Silver lost its monetary utility to gold a century ago. It's not money. Gold is still money for now, but you want to skate to where the puck will be, not where the puck is.
The middle ground is that you require proof of work for free users, allowing paid users to bypass the work.
I agree that making a relay operator do spam prevention, basically as a full time job, is a great way to repeat the mistakes of SMTP.
But our focus, as a community, on mobile clients at this time makes it difficult to pursue without alot of pain in the UX. I think we need to get serious about spam, though. Before natural protocol ossification happens.
I can fix it in 2 hours. With your help I can fix it in 2 days.
love seeing #[0] on tv preaching the gospel
So easily and quickly you explain that Bitcoin can't be printed.
"There are two things I can guarentee ... I'll die and there will only ever be 21 million BTC. The only two things I can really value are my life and my Bitcoin." - #[0]
I think the best solution to this is to use a hybrid cloud, phone and brain/hardware wallet. Fully self-custodial but with less stress on a person to always remember the seed phrase that may be loaded onto a hardware wallet if needed (if the phone+cloud is unavailable)
A service that is sorta like this is https://nunchuk.io/, also I think @#[0] is building something like this at Block with their own hardware wallet development, last I heard.