My design combines both concepts but doesn't need PoW (formerly I had unprofitable PoW but hence replaced it with something better)! That is a very strong hint for you.
Would you mind telling us more about your discarded idea of unprofitable PoW?
Some time ago, I came up with such a concept myself:
https://bitcointalk.org/index.php?topic=1591011.msg15981017#msg15981017My basic idea was to use PoW as means of "honing" your address/account, so that mining would become more beneficial for low-scale miners than for big players.
The only participants possibly motivated to do unprofitable PoW are those who are issuing transactions.
If we argue for an
altruism-prime motivation (and make the perhaps incorrect assumption that it doesn't matter that it is an undersupplied public good!), they will willingly burn the larger of:
- A reasonable transaction fee burned as PoW.
- Their CPU PoW hashrate at fractions of their current electric bill.
Neither of those even with millions of users (and especially if you expect them to be on mobile) will be sufficient to secure the chain against powerful attackers such as botnets with gaming rigs and hijacked Amazon EC2 or other VPS cloud accounts.
I also suggest these two References from my (yet unpublished) white paper:
Also (even unprofitable)
mining on CPUs enables 51% rented hashrate attacks! Kiss Monero's (and Zcash's) ass goodbye if they don't get an ASIC implementation. Komodo might possibly be a better bet because
@jl777 adopted my suggestion to use Bitcoin's blockchain for security.