So basically the economic incentive for a double spending attack on NuBits is too low to justify such an attack because NuBits transactions are sustained by NuShares’ blockchain which is controlled by PoS and in PoS to perform such an attack you need 51% of the whole “stake” and the right timing.
So it comes down to the fact that in PoS, the 51% attack is equivalent to economic suicide.
By the way, here, to perform a 51% of NuBits, would you need 51% of NuShares or 51% of NuBits?
I fail to understand the way NuBits are represented in the NuShares blockchain…I need to do much more research…
As the minting is done solely with the NuShares, you need NuShares to attack the minting process. NuBits transactions are in the same block chain but the NuBits have nothing to do with creating blocks. https://nubits.com/about/white-paper#voting gives a hint how the block chain is secured, but you need to read between the lines.
I don’t know, but I assume that NBT transactions are similar to transactions we already know from other implementations. So NBT might simply be the balance (aggregated inputs and outputs) on addresses.
A dev will know in greater detail.