[touchofevil]

This is one reason why I think Nano (Nano.org) will eclipse Bitcoin for pure transfer of value transactions. Nano uses a block lattice that doesn't require mining. The transactions are instant and feeless b/c of this. There is a tiny bit of PoW on the sender's device to prevent spam transactions.

[iainmerrick]

Hmm, how small is “tiny”?

I suspect it would either be too small to be a deterrent, big enough to be wasteful at scale, or both. Is there really a sweet spot that avoids both of those?

[touchofevil]

This site claims that a single Nano transaction taking 0.112 Wh vs a Bitcoin transaction taking 950kWh. (note Wh vs kWh) https://isnanogreenyet.com/

Check Nano's FAQ regarding "Is Nano vulnerable to attacks?" here https://nano.org/en/faq