PAI News ? - May 18, 2020

PAI News ? - May 18, 2020


A snapshot of the Friday’s Livestream AMA: Chuck Ng (top left), Dr. Mark Harvilla (top right), Dr. Yongzheng Jia (bottom left), and Nikhil Jain (bottom right)

Announcements ?

  • Thank you everyone for joining the Livestream presentation last Saturday morning. ? It was a huge success and we appreciate your ongoing support. You can find the slides here:

  • The Project PAI Contributors will do additional livestreams in the future focused on specific technical details of projects like Proof of Useful Work. Stay tuned for more information!
  • The PAI Coin Pool promotion is ongoing! Stake 1,000 PAI Coin or more for at least 3 months and earn a 10 PAI Coin bonus. You can also earn the bonus by mining 40,000 Lucky Hashes. The promotion expires on Friday, May 22 at 11 PM Beijing Time.

(More) ? Frequently Asked Questions

PAI Hybrid Consensus

What is a Voting Service Provider (VSP)?

Proof-of-Work (PoW)-based cryptocurrencies rely on the massive hashing power of miners’ hardware to regularly keep adding new blocks to the blockchain. PoW mining can be very expensive when it requires dedicated hardware like Application Specific Integrated Circuits (ASICs) or Graphics Processing Units (GPUs). These costs severely limit the access of low-budget entities, like individuals and small companies, to mining. To mitigate this, some cryptocurrencies use a Proof-of-Stake (PoS) mechanism, whereby a miner must stake some cryptocoins to receive a reward. This eliminates the need for special hardware and high electricity costs, but is itself sensitive to other kinds of attacks.

Combining PoW and PoS via a Hybrid Consensus protocol significantly reduces the individual drawbacks of PoW or PoS when used alone. In PAI Coin’s Hybrid solution, PoW miners must include votes for the previous block. These votes are cast by randomly selected entities that previously expressed their intention to participate by purchasing tickets. Since the process is automated, voters must have at least one computer permanently online and ready to vote. While this is not even close to the hardware requirements for PoW-only cryptocurrencies, it might still be an issue for individuals wanting to participate. Even if it might be acceptable for desktop users to leave their computer permanently online, it’s practically impossible for Mobile Wallet users.

This is where Voting Service Providers (VSPs) come into play. VSPs are third-party entities with high availability systems for voting on behalf of a ticket buyer. When buying a ticket, a participant can delegate the voting rights to a VSP.

Technically, the delegation of voting rights is done by creating a ticket purchase transaction with two contribution outputs: one having the participant’s address and one specifying a 1-of-2 multiple signature (multisig) address built from an address of the participant and an address of the VSP. When the ticket is selected to vote, the VSP creates the vote in such a way that the reward is split proportionally between the participant’s address and the multisig address. The VSP will then be able to spend its reward, while not touching the participant’s reward. The VSP reward is also known as the VSP fee. The correctness of the vote transaction is enforced by the consensus rules.

This approach is safe for both the participant and the VSP for several reasons. The participant has exclusive rights to the share of the reward that is contributed to with his/her address. The VSP cannot spend this part of the reward because it does not have access to the corresponding private keys. The VSP, however, has access to the share of the reward that is contributed to with the multisig address.

In the highly improbable case that the VSP does not vote when needed, the participant can redeem the entire initial stake, including the VSP fee, because he/she has one of the multisig address components. For the same reason, the user can even vote directly when the ticket is selected. The only funds that cannot be restored are the ticket purchase transaction fees.

In conclusion, VSPs are an important component of a Hybrid cryptocurrency ecosystem that facilitate the participation of virtually any user in the voting process and the reward sharing, with as little as a mobile wallet on a smartphone. They play an important role in the complete decentralization of cryptocurrency mining and reward sharing.

Proof of Useful Work

What is Proof of Useful Work?

Proof of Useful Work (PoUW) is a consensus protocol being researched and developed by Project PAI Core Contributors, in an effort to:

  • Extend the utility of PoW consensus;
  • Facilitate arbitrary “on-chain” computations;
  • Reduce wasteful energy expenditure

Proof of Work is like a lottery: Every participating miner has a chance to win the block reward for mining a new block, and this motivates many users to participate in mining. The more people that participate, the more decentralized the cryptocurrency network becomes, but the less likely it is for any individual miner to win the block reward—unless he or she buys more entries into the lottery. The only way to “buy more entries” is to mine at a higher hash rate, which costs more money to maintain, and expends more electricity.

Because of this never-ending race for more lottery entries—higher hash rate—the Bitcoin network currently consumes over 66 Terawatt-Hours of electricity per year, roughly equivalent to the energy consumption of a nation of 10 million people. And, because it’s inherently PoW based, PAI Coin could be on the same path.

Such facts motivated some Project PAI Contributors to investigate changes to the PoW protocol which would rely on the notion of “Useful Work,” i.e., any “work” that a third party has requested to be completed.

While lottery entries to Bitcoin’s PoW consensus simply require a random number (literally), lottery entries to PAI Coin’s PoUW consensus require a number which is provably associated with a unit of Useful Work. So, while the energy consumption associated with PAI Coin PoUW may well still be quite large, it would be spent on calculations that would presumably be done anyway and elsewhere (e.g., on a cloud computing platform, in a server farm, on a desktop computer, etc.).

Most cryptocurrencies only have one type of user—transactors, i.e., those who exchange the cryptocoin as a currency, whether for sale or trade or in exchange for other items for purchase. PAI Coin PoUW, instead, would have two types of users: transactors, but also… requestors. Requestors are those who submit data and computational job requests to the PAI Coin network for a fee. For example, a corporation might submit a request to mine customer review data; an academic might submit a job to train a Machine Learning model; or an epidemiologist might submit a job to simulate the spread of a virus in a population. The possibilities are endless.

By rethinking the origin of lottery entries in the Proof of Work mechanism, Proof of Useful Work aims to facilitate these arbitrary on-chain computations, thereby expanding the utility of traditional Proof-of-Work consensus, and reducing wasteful energy expenditure.

Remember — If there’s something else you want to know, just ask on PAI Forum!

PAI Weekly Updates ?

PAI Coin Pool

Last week, the Referral and Promotional Bonus systems were successfully launched! ?You can now earn extra PAI Coin by referring your friends, family, and followers. It’s easy — just copy your Referral Link (available in your PCP profile) and send it to everyone you know.? You can earn Tier 1 Referral Rewards based on the activity of anyone who signs up with your link… and Tier 2 Referral Rewards based on the activity of anyone who signs up using theirs.


This week, an updated GUI ?, previewed above, will be released allowing you to see exactly how much progress you’ve made toward an ongoing promotion.

Speaking of which…

Stake 1,000 PAI Coin for 3 months or longer before Friday, May 22, 11 PM Beijing Time and earn a 10 PAI Coin Bonus!

PAI Hybrid Consensus

Here’s a snapshot ?of some of the commits / PRs by our developers last week:

PAI Forum & PAI Pass

The PAI Forum with PAI Pass integration has been stable in testing. The team has been making updates to the user experience and backend infrastructure. Those changes will go live this week. In addition, it became clear that accessibility was a concern for some geographic regions -- so testing has been ongoing to determine a production release hosting solution. Once latency and accessibility issues have been resolved, the forum with PAI Pass integration will be made available to the community in place of the existing Paiforum.

You can also find more information about PAI Pass on the PAI Pass Whitepaper here.

Questions? Comments? Feedback?

Sound off on PAI Forum! ?


Thank you for your support!