I'm still surprised that people are still singing and dancing about the risk of 0 confirmation transactions, or having to wait 10 minutes to buy a coffee, burger, laundromat token, etc.
There's plenty of topics on here and other websites that explain why no one would bother trying to double-spend attack such a small purchase, because it would take
significant cost and effort to pull it off successfully.
There's only 2 things you need to do to stop the average person trying to double spend:
- Be connected to the internet, listening to other bitcoin transactions
- Check the transaction fee meets the protocol requirements
If you do those, then you're very safe. The cost for the "attacker" to double spend would far out weigh the reward of the the goods/services that they're attempting to steal from you.
Accepting 0 confirmation transactions is safer than credit card, and safer than coin operated machines that can be tampered with or raided in the absence of supervision.
you can hook all washing machine to basically a single mobile connection, but preferably you're gonna want a hard line.
this! if you fronted up the cost of a hard line you could have wifi running and attempt to charge people to use it while they're waiting for their washing... not sure if that would be successful these days where almost everyone has cheap mobile data.
