[Please forgive me my repost. I accidentally posted the thread in the wrong forum]
https://medium.com/@cv.alkan/decentralized-objective-consensus-without-proof-of-work-a983a0489f0a#.q30wcxthyIn my recent article, I propose a novel dual-token PoS model that aims to decouple rewards from resources (while preserving a sufficient incentive to build blocks).
The general idea is to have special accounts (minter accounts) as a second token. In contrast to regular accounts which can be created for free, a minter account pays out interests on its current balance. These accounts cannot be created at will, but are given to the minters who successfully build blocks. Such child accounts, having a market value, can then be sold to new owners. As the interests are paid to every minter account (not just the one that creates the block), a single entity has no incentive to own more than one account, while the trade with existing accounts is strongly disincentivized.
The blockchain is exclusively built by the owners of minter accounts whose number will grow over time. As a consequence, the consensus gets increasingly decentralized and secure. A 51% attacker would not only have to pay a lot of money to get enough accounts, but he would also need to spend a lot of time (in fact, he would have to keep buying child accounts for a period of time corresponding to the current age of the blockchain).
Furthermore, the economic value represented by the minter accounts allows for an effective punitive scheme to defend against the Nothing-at-Stake issue, without the need of locking up funds forever. Pre-committed hash chain are used for random selection of the next minter and at the same time provide DDoS-resilience.
And last but not least, the model makes use of heartbeat transactions which have to be issued by minter accounts from time to time. These transactions must include a TaPoS-like reference to a recent block of the chain which allows to detect long-range history attacks even if the attacker possesses more than 50% of old account keys.