Proof-of-Stake (PoS) Tickets

Overview

The multiple functions of the EXCC’s exclusive Proof of Stake Protocol

1. It can be used to give stakeholders the privilege to vote when decisions are made regarding the EXCC blockchain. A situation where the stakeholders vote to allow a change, the blockchain will automatically permit the new function to become active. To find more information regarding voting view the How to vote.
2. It presents a medium through which the stakeholders can monitor the performance of the miners. The stakeholders have the privilege to vote that a block is invalid even when it is in accordance with the consensus rules of the network. This function checks the inappropriate actions of miners such as mining empty blocks.
3. Older holders of EXCC can lock their deposited coins for a long period while prospecting the additional coins that will be awarded from the Block Reward.

Understanding the Proof-Of-Stake System

Stakeholders will be required to secure a ticket for eligibility to be a part of the stake mining process. Tickets can be secured by locking an amount of EXCC. With these tickets, stakeholders can cast a vote per ticket. After voting, the ticket delivers a reward in addition to the original value of the Ticket Price. The tickets for the voting process are randomly selected, the duration of this voting exercise can last from between 1 to 71 days (14 days average), and however, there is a 0.5% probability that the tickets can become invalid before selection for a vote. Upon expiration, the original Ticket Price is refunded without a reward. For each mined block, there must be five votes; if the votes fall below five, a deduction will be made from the miner's reward as a penalty. The mined blocks are permitted to have as many as 20 new ticket purchases. It takes about 256 blocks for a new ticket to mature before it can be added to the Ticket Pool, and eligible to be selected during the voting process.

Some crucial variables that users should know while staking include the following:

• For every 144 blocks (approximately 6 hours) the algorithm for the stake difficulty runs a calculation to generate a new Ticket Price to maintain the Ticket Pool size so the target size of 40,960 tickets will not be exceeded. In this instance, the 144 block window is called the Stake Difference Window Size.
• For every single 144 block window, users will be mandated to pay the Ticket Price/Stake Difficulty price.
• The Ticket Pool refers to the overall number of the tickets available on the EXCC network.
• The Ticket Fee (ticketfee) refers to the rate that is mandatorily added to the ticket purchases as an incentive to encourage Proof of Work miners to add the ticket to a new block. The Ticket Fee is usually represented as the EXCC/kB fee rate per ticket purchase. This means that for transactions of higher values, the user will pay a higher fee. For example, the purchases made for solo staking tickets are valued at about 300 Bytes; this indicates that a Ticket Fee of 0.3 EXCC/kB will require 0.1 EXCC to be spent only when the ticket is added to a block.
• At lower Ticket Prices for a single Ticket Window, users can witness the formation of a market, where multiple stakeholders will attempt to buy tickets before the window closes. However, if the Ticket Price is not very low and the deal seems profitable, the default rate - Ticket Fee of 0.001 EXCC/kB will be sufficient to be added to a block. If a ticket is selected for a vote, the wallet with the voting rights must be online to cast a vote or the ticket will be recorded as a miss, and the user will not be rewarded for that ticket. The stakepools offer a solution for users who cannot be online 24/7 to vote.
• The stakepools are used by the stakeholders to carry out transactions for ticket purchases that provide stakepool voting rights for a user’s tickets. Voting can be done on the user's behalf for a small fee (usually less than 7%) paid for participation. The fee is charged to enable the maintenance of the three servers being hosted to run the stakepool. It is called the Pool Fee charged for the minimal PoS reward.

The Lifecycle of a Ticket

It is quite easy to buy tickets for the PoS, after purchase, the ticket on the mainnet (there are multiple parameters for test net) will pass through different stages during its lifetime.

1. After purchasing a ticket through Exilibrium or the exccwallet, the individual transaction charge for each purchase is expected to be Ticket Price + Ticket Fee (ticketfee).
2. The purchased ticket is added to the mempool where it will be kept until it is mined by PoW miners. A maximum of 20 new tickets are mined into the different blocks.
3. Blocks with higher Ticket Fee for transactions are used for the high priority tickets. It should be noted that the Ticket Fee is valued at EXCC per KB for each transaction. Some transaction sizes such as the solo ticket purchase are 298 bytes, while others such as pool ticket purchases are 539 bytes.  
4. A - This is for tickets mined into a block; it assumes the state of an immature ticket for 256 blocks (approximately 10 hours). The immature tickets are not eligible for voting, and at this stage, the ticket fee cannot be refunded.
   B - In the case where the users’ ticket is not mined, Ticket Price and Ticket Fee are refunded to the account used for purchase.
5. At maturity (256 blocks), the ticket is added to the Ticket Pool where it can be used for voting.
6. The possibility of a ticket being selected for voting is dependent on a Poisson distribution which is done in an average of 14 days after which the ticket stands a 50% chance of being voted.
7. Regarding the size of the target pool (40960 tickets), randomly, the tickets have a 99.5% chance of voting within a period of 71 days (approximately 2.3 months). It is expected that the ticket will be invalidated if it is not voted within this time-frame. Subsequently, a refund of the Ticket Price will be made.
8. In a situation where a ticket is unresponsive or when two valid blocks exist close to each other, it may miss the call to vote, if this happens, the user will receive a refund valued at the original Ticket Price.
9. If a ticket is voted, or missed/invalidated, the funds (price of ticket and the subsidy, excluding the fee) attain a maturity status for the next 256 blocks before it is released. In the case of missed/invalidated tickets, the transaction will be revoked, and the locked ticket asset is released. Please Note:  Only missed tickets can be submitted for a revocation, users are not permitted to proceed with the revocation of a ticket until it has been recorded as missed.