This whitepaper describes a novel type of blockchain consensus that will be utilized in Stealth (XST). Consensus in XST will be decided by a round-robin block certification system that is purely economic, where block rewards are results driven. This system, called qPoS (quantum proof-of-stake), has a group of signatories that produce blocks in rounds. Signing privileges are tokenized as digital assets, called stakers. As signatories produce blocks, their stakers gain not only influence on consensus, but also earning capacity. Both increase with the square root of the net number of blocks produced by the staker. Existing stakers are transferrable, and new stakers can be purchased from the blockchain through a process that eliminates the purchasing money from the XST supply.
In qPoS, block signers are queued at the beginning of each round. When a given staker has its turn, the staker has 5 seconds to sign and submit a block to the network. If the staker does not produce the block in this time, it is penalized with a “miss” that reduces by 1 the net number of blocks the staker has signed. Additionally, the staker cannot claim a reward for a missed block and may be subject to termination based on rules described below.
The ruleset for qPoS enforces that stakers will be rewared for not only producing blocks, but for a history of good behavior. Good behavior is quantified by a metric that herein is called “weight”. Weight is calculated as the square root of the net number of blocks a staker has produced over its lifetime. This highly economic and results-based system stands in contrast to systems described as delegated proof-of-stake (dPoS). Unless carefully planned and conducted, dPoS signing rights rely on the political standing of the signatories. These political block chain systems are susceptible to corruption in that signatories may gain favor with parties who have overwhelming stake originating from insider status, leading to problems with wealth distribution as well as blockchain performance.