For the bday paradox I am agreeing, I am really meaning that it does not make the
t figure of 1/3 naive. The quorum figures are well established mathematically, however not really related to stopping the birthday paradox, a higher % quorum just makes it more difficult. I think it’s best to just say regardless of all of this if we have a network with many sections (which disjoint sections vastly reduces as pure kademlia has as many sections as addresses ) then we need mechnisms that distribute attackers as efficiently as possible and at the same time drive costs of such an attack as high as possible.
So to calculate the % an attacker needs we do need to consider
- The quorum
- Number of sections
- Nodes per section (you and @tfa are doing this part and brilliantly)
- Node age (infants, adults etc. to force time and effort to be increased by a considerable amount, i.e. an attack can be reasoned to be, if it costs the attacker X much more than any possible return then it’s more secure (never totally)).
- Forced relocation
- Targetted relocation (not allowing a node to create an address in a section, but create an address between the furthest 2 nodes in a section).
- Penalties (huge area as @mav poked about at a good bit, but much more to do there).
- I am sure I have forgotten a lot here …
After all that there is the economics (or cryptoeconomics as some say in a confusing and elitest way ) Where safecoin comes in, I prefer to keep this to way last as humans are, well humans