Upcoming GRAFT Network Difficulty Algorithm Update

The code release for the upcoming GRAFT network update, which includes ASIC resistance, enhanced difficulty adjustment algorithm, and minor bug fixes, is almost ready to go, and we are on track to release it on Monday, April 9th, with the actual switch scheduled to be triggered around April 16th (the block number will be announced later). Currently, we are conducting regression tests. The ASIC resistance code in conjunction with the new difficulty algorithm is supposed to minimize the possibility of hashrate attacks – when significant hashrate power (generated by ASIC or large GPU miner) is connected for relatively short period of time and making it difficult for other miners to compete and solve the blocks, until the existing algorithm adopts to a new hashrate and adjusts the network difficulty. This is how the existing algorithm reacts to sudden hashrate spikes in the mainnet: The following graph shows how the updated algorithm adjusts the difficulty much better after the simulated hashrate attacks: Although we think the upcoming network update will be sufficient to protect the blockchain from the majority of hashrate attacks, we are also working on original, even more enhanced version of the difficulty adjustment algorithm, which is supposed to provide even better, more “symmetrical” and balanced response to any hashrate fluctuations. Since such enhancements require significant testing, which is very time consuming, we are planning to include it in the next network update (the one after the upcoming update on April 6th), along with the merge of recent Monero changes. As usual, we will follow up with more details soon. Stay tuned!

Consolidating “US” and “EU” GRAFT Mining Pools Into a Single Community Pool

GRAFT team is going to consolidate the “US” and “EU” mining pools into a single community pool, which is supposed to increase the efficiency and reduce the costs of maintenance and support. Initially, at the moment of GRAFT blockchain launch on January 16th, 2018, two pools were supposed to ensure better decentralization and stability of the new blockchain; however, rapid growth of GRAFT popularity and mining community made this issue irrelevant shortly after the launch. Now Graft team is seeking a better distribution of the hashrate load, and as the network grows bigger, we are decommissioning one pool to allow operators of independant pools to gain a bigger market share.

The URL of the consolidated pool is going to be grftpool.com. Users of both current pools will be automatically redirected from the old urls. Miners connected to the “EU pool” will not be affected. Miners connected to the “US pool”, which is going to be shut down, will be receiving their payouts in full after the mining on the US pool is turned off. The switch will take place on April 1st. We recommend all miners currently connected to us.pool.graft.network to switch to eu.pool.graft.network as soon as possible in order to avoid any unexpected issues. Happy mining!

Upcoming GRAFT Software Release and Major Network Update

As was promised in the last week’s post, we provide more details regarding the upcoming major network update. The mainnet release of GRAFT software update has been scheduled tentatively for April 9th, with the major network update to happen on April 16th (specific number of the block that triggers the update, which is hardcoded into the node, will be announced on April 9th).

As a reminder, major network update means that if you are running the GRAFT network node (graftnoded), you must upgrade to the latest software release between April 9th and April 16th. If you do not upgrade your node before April 16th, it will be disconnected from the mainnet. Note that users of mobile and desktop wallets are not affected by the network update and don’t need to do anything – as long as they are still connected to the default proxy supernodes (if you are connected to your own supernode, however, do not forget to upgrade the underlying network node).

This network update will include two major changes and some minor bug fixes. The major changes are the Cryptonight update (for ASIC resistance) and new difficulty adjustment algorithm (for preventing hashrate attacks and stabilizing the block intervals). We are still testing the new difficulty algorithm to determine the best set of parameters. The testing results will be published next week. Stay tuned!

Brief Update on Status of ASIC Resistance and Difficulty Algorithm

GRAFT core development team is currently in R&D phase working on both ASIC resistance and improved difficulty algorithm, which will be included in the same network upgrade (hard fork). As we unfold various challenges and conducting addtional testing, we plan to release the details and delivery dates within a week. Stay tuned!

GRAFT Anti-ASIC Fork

GRAFT team shares the same concerns raised by Cryptonote/Cryptonight community associated with creating a special hardware (ASIC) for Cryptonight mining. We realize that enabling ASIC (Application Specific Integrated Circuit) at this point may introduce a risk to stability, decentralization, and even very existence of GRAFT blockchain. After thorough review we decided to support the anti-ASIC movement and add an ASIC-resistant code in the next fork. We will follow up with more details about the implementation and timelines soon. Thank you for your support, stay tuned!

Recent Updates in GRAFT Wallets: Send and Integrated Addresses

GRAFT provides CLI wallet, mobile wallets, and desktop wallets for Windows and Mac. All wallet apps now are able to send GRFT to other wallets, which is functionality that initially was available only in CLI wallet. We also added support for longer integrated addresses required for sending funds to exchanges.

Send vs. Pay vs. Transfer

It is important to understand the difference between current Send function and future Pay and Transfer functions. To add to the confusion, Send in mobile and desktop wallets is the same as Transfer in CLI wallet. So let’s see why these three functions are different and what they are designed for.

Send (aka Transfer in CLI wallet) is “traditional” transaction between GRAFT addresses. It is implemented by creating a transaction and adding it to the next block on the blockchain. This is slow process which can take from 2 to 10 minutes (depending on current blockchain “traffic” and interval between the blocks). Also, the balance in the recipient wallet becomes “unlocked” (available for next transaction) only after 10 confirmations (10 blocks) which adds another 20-30 minutes. GRAFT Send is similar to bank wire transfer; however, it is still much faster than wire (minutes vs. hours) and cheaper (cents vs. dollars).

The good thing about Send is that it can move GRFT from any address to any address, no matter what GRAFT app you are using, including third party bodies such as exchanges. The downsides are low speed of transaction and the fee paid by the sender in addition to the transaction amount (although GRAFT set a very decent fee which is lower than in most other cryptocurrencies).

Pay is based on GRAFT RTA (real time authorization) technology and conducts a payment transaction between GRAFT wallet and GRAFT POS (point of sale), or any POS compatible with GRAFT or equipped with hardware payment terminal supporting GRAFT. Pay is currently only implemented on RTA testnet and still in alpha phase; it is currently disabled on mainnet. RTA is one of the most significant GRAFT features which facilitates instant payments between buyers and merchants using GRFT and other cryptocurrencies, both at brick and mortar stores and online. GRAFT Pay is similar to credit/debit card payment; however, unlike credit/debit card payment, GRAFT Pay is absolutely secure and private: the identity of sender and recipient, the transaction amount, and even transaction fee are invisible to the public looking at the blockchain.

Main advantages of Pay comparing to Send are instant authorization (within a few seconds) and no fee paid by the buyer (sender) as the fee is paid by the merchant.

Transfer allows limited number of transactions between user wallets free of charge (no fee paid by either sender or recipient). This function is available only to authenticated users, i.e. the users who agree to partially “compromise” their privacy in order to get additional benefits from the network, or to the VChain owners (you can find more info about VChains in the latest version of GRAFT White Paper).

GRAFT Transfer is similar to bank ACH transfer: both are free. GRAFT Transfer, however, is much faster then ACH (seconds vs. hours/days). GRAFT Transfer is scheduled for implementation before the end of 2018.

It is important to mention that all three methods of GRAFT transactions are still based on GRAFT Blockchain which means they provide full security and privacy to both sender and receiver.

What is Integrated Address?

Standard GRAFT Address contains a pair or public spend and view keys packed into a single string using special encoding. This is the standard public address you typically see when you want to receive GRAFT in your wallet:

Standard GRAFT address is 95 characters long and always starts from letter “G”.

Integrated GRAFT Address contains unique Payment ID in addition to the pair of public keys. Although integrated address does not hide your keys or payment ID from public view, it is always different because of the different payment ID. Many exchanges require using integrated address in order to top up the balance. GRAFT Integrated address is 106 characters long and also always starts with letter “G”.

Important Changes in GRAFT Design

Combined PoW/PoS (proof-of-work/proof-of-stake) algorithm was one of the most important proposals in the original GRAFT white paper. After getting some real-life experience with running the mainnet since January 16th, and based on feedback received from multiple miners and potential supernode owners, the GRAFT team realized that there is big difference between “combined” and “coupled”. The proposal of the “combined” PoW/PoS was in fact “loosely coupled” PoW/PoS. The problem with coupled PoW/PoS is that the PoW power is mostly consolidated in a few large pools, which limits the ability to create a large number of independent full supernodes. This process of consolidation happened very fast because 1) we use CryptoNote/CryptoNight protocol which is very well known in miners’ community and 2) our project received good attention and massive support of miners community, with many miners spending significant resources to contribute to the network hashrate (which is great!).

With that said, we decided to make the following changes in RTA (“real time authorization”) design:

1. “Decouple” PoW and PoS, so the full supernode will require only the stake (PoS), effectively eliminating the requirement to mine a block in order to run the full supernode. The full supernode will only require a stake (50,000 GRFT) in order to be eligible for processing RTA. We modify the authorization sample selection algorithm so instead of looking at recent mined blocks it will compare the hash of the supernode’s PoS wallet with the hash of the last mined block (height – 30). The main idea here is that the selection is random while the result is deterministic for anyone who calculates the formula. The Tx fee is still equally distributed between the members of the authorization sample; the miner also receives the share of the fee.

2. Introduce 4-tier stake model where a higher tier has a greater chance to be selected into authorization sample, while the selection process is still random.

50,000 GRFT – tier 1

90,000 GRFT – tier 2

150,000 GRFT – tier 3

250,000 GRFT – tier 4

Each tier participates in a random selection of 2 sample supernodes (a total of 8 full supernodes). Thus, naturally, tier 4 supernode has more chances to be selected due to the limited number of tier 4 supernodes. “Empty” spots are filled by the higher level tiers (or lower in absence of higher). This algorithm is also adaptive as it will “regulate” the average number of full supernodes on each level.

3. Allow delegated stake. Balances from multiple wallets can be “delegated” to a single full supernode in order to form a stake significant enough to run a full supernode. The earnings are distributed between the wallets according to their stake share. Minimum balance for delegated stake is 5,000 GRFT.

4. Introduce 2-tier transaction fee. The RTA (“instant confirmation”) Tx fee will be set to 0.5% of Tx amount or 0.01 GRAFT, whichever is greater. RTA transaction is used for real time point-of-sale purchases, in store or online, similar to credit/debit card payments. The regular (“slow”) transfer fee will remain the same: 0.1% or 0.01 GRAFT, whichever is greater, for micropayments (Tx amount less than 1,000 GRFT), and Log(1000) of Tx amount – for Tx amounts greater than 1,000 GRFT. This transaction type is used for transfers between accounts, similar to ACH bank transfers.

Although these changes may resemble some existing implementations of PoS and masternodes, GRAFT solution is still a unique combination of most private blockchain protocol (CryptoNote), advanced principles of PoS and multi-tier networks, and new approach to crypto payment processing with features like low Tx fee, the fee charged to the recipient, functional separation between the Wallet and Point-of-sale apps, various retail transaction types, service brokers, and more. GRAFT development team has already started design and implementation of all the features and changes above.

Sample Earnings / ROI Calculations

As can be seen from this calculator, the full supernode income depends on 1) number of transactions in the network, 2) number of full supernodes in the network, 3) average transaction amount, and 4) the stake tier of the full supernode.

The following were the assumptions for these calculations:

Additional Income Sources for Supernodes

In addition to transaction fees, the full supernode owners can also charge Service Broker fees. Service Broker fees are the fees that customers pay to the full supernode owner in return for Service Level Agreements (SLA) and DAPI access. These fees can be metered or flat, depending on the business arrangement the supernode owner wants to offer. More on this later…

The Beauty of Cryptography: Why We Chose to Build GRAFT Platform on CryptoNote Protocol

Is cryptography a science or an art? Its fruits are beautiful, and only true art can produce a beauty! Dostoevsky said “beauty will save the world.” The beauty of cryptography will save privacy and security of our world in a time of total connectivity.

Look at Elliptic Curves, a public key encryption algorithm used in digital signatures by both Bitcoin and CryptoNote protocols. They are beautiful even if you don’t understand the math. They become even more charming when you start understanding. In my recent book, Bitcoin for Nonmathematicians, I tried to explain, without higher mathematics, in layman’s terms, how Elliptic Curves work. It’s not impossible to understand them if you really want to. But they are huge and mind-blowing. And they are just one piece of CryptoNote protocol, which is one of the highest achievements of cryptography.

CryptoNote stands out of all other blockchain protocols because it provides something we all need: privacy. We often take privacy for granted and only regret when we lose it. Ironically, Bitcoin and its derivatives take a step backward in privacy area comparing to older payment technologies such as cash or even plastic cards which became an inglorious symbol of compromised security and privacy. Bitcoin creator(s) either did not think about privacy, or simply did not have enough time to resolve all the problems, which is absolutely understandable as they had even more important problem to solve: the very existence of blockchain technology.

CryptoNote keeps all the benefits of blockchain technologies, which are well known, while “returning” the lost privacy features: untraceable payments, unlinkable transactions, blockchain analysis resistance, and confidential transaction amounts. On top of that, Graft adds confidential transaction fee amounts to complete the picture. CryptoNote creates a perfect solid foundation for building a variety of industry-related features which Graft brings to light in order to conquer the world of payments.

Cryptocurrency Service Brokers

A set of cryptocurrency service brokers will be available for each major cryptocurrency listed on https://coinmarketcap.com/, starting from the top of “top 10” by market capitalization. The service brokers will boost liquidity of each cryptocurrency by enabling various payment options on both buyer’s and merchant’s sides of the transaction. The cryptocurrency service brokers will be implemented in collaboration with existing or/and newly created exchanges. Multiple choices for each cryptocurrency eventually will be available, so they could compete in order to provide better rates and services. The variety of services and automated sign up, selection, and execution processes will keep the decentralized character of the network.

Every single set includes four service brokers implemented for each cryptocurrency. Pay-in and Top-up brokers work with the GRAFT wallet app to allow a buyer to use the selected cryptocurrency as a payment method when making a payment to GRAFT points of sale (POS), native wallet apps, non-GRAFT POS integrated with GRAFT DAPI, or non-GRAFT POS that accepts the selected cryptocurrency. Accept and Payout brokers work with GRAFT POS to allow a merchant to accept the selected as a payment method while conducting payment transactions with GRAFT wallet app or NEM wallets.

Pay-in Broker

Pay-in broker works with GRAFT Wallet App to facilitate a payment to a native cryptocurrency wallet or non-GRAFT POS accepting the cryptocurrency.

In this scenario, the Pay-in Broker creates a regular cryptocurrency transaction in native format for the particular network and sends it to the native recipient address. There is a network transaction fee which is in this case charged to the sender because the transaction is not fully facilitated by the GRAFT network. The payment is not processed instantly because the recipient is not participating in Graft network. This scenario is less beneficial than GRF transaction for both buyer and merchant because of the lower speed of transaction and transaction fees paid by the buyer. However, it is supported by Graft in order to keep the buyer’s wallet flexible and useful even outside of the Graft ecosystem.

Pay-in Broker will instantly exchange necessary amount of GRF from buyer’s account to the selected cryptocurrency. The buyer pays a small exchange fee to the Pay-in Broker, which can be paid in a form of exchange rate.

Top-Up Broker

Top-Up Broker works with GRAFT wallet to perform on-demand exchange of the selected cryptocurrency to GRF in order to allow payments to GRAFT POS or non-GRAFT POS integrated with GRAFT DAPI.

This scenario is the most beneficial for both the buyer and the merchant because all the fees (including the network fees of the target cryptocurrency) are paid by the merchant, and payment is approved instantly. For the buyer, the benefits are obvious – no fees associated with the payment, and ability to pay with the target cryptocurrency to a merchant that does not accept it. For the merchant, it is important to get instant authorization in order to be able to serve more customers in real time, and accept payments in various cryptocurrencies. The fact that all the fees are paid by the merchant, just like with “traditional” credit/debit card payments, allows much better customer conversion rates.

Top-Up broker can also process exchanges on demand with larger amounts and better rates.

Accept Broker

Accept Broker works with GRAFT POS to facilitate acceptance of selected cryptocurrency as a payment method in case the buyer does not have GRAFT wallet. Accept Broker receives funds in selected cryptocurrency and converts them to GRF.

The (selected cryptocurrency) network transaction fee is still paid by the buyer, unless the buyer uses GRAFT wallet app. If the buyer uses GRAFT wallet, the wallet recognizes the GRAFT POS and automatically converts the payment transaction to instant transaction in GRF.

The merchant payout is processed by Accept Broker in GRF instantly, hourly, daily, or on demand, depending on settings, or in other cryptocurrency or fiat currency if corresponding payout brokers are activated.

From the buyer’s point of view, the transaction looks similar to regular transaction between native cryptocurrency wallets.

Payout Broker

Payout Broker works with GRAFT POS to facilitate merchant payouts in selected cryptocurrency. Payout broker exchanges GRF available on the POS account to selected cryptocurrency and makes deposits to the associated account instantly, hourly, daily, or on demand, depending on settings.

Payout Fees

Payout fees/exchange rates for payouts processed by either Accept or Payout service brokers may vary on frequency of the payout. Depending on transaction volume, daily payouts can cost significantly less than instant payouts since the broker can accumulate more funds and pay just a single network fee for single payout transaction, comparing to paying a separate fee for each instant payout transaction.

GRAFT Merchant Tokens: Introducing VChains

Merchant token is a simple smart contract that allows creating a private token that belongs to its owner. Unlike some other smart contract and token platforms, creation of GRAFT merchant token does not require any programming and can be done by anyone.

The business features described below are typically associated with using complex third party service providers and high implementation costs, which makes those services inaccessible for small to medium size businesses and expensive to large businesses. GRAFT Merchant tokens allow any merchant to implement those important business features with minimum efforts and low cost.

Types of Merchant Tokens

Store Credits

Store Credits are typically utilized by merchants for performing purchase returns and exchanges, when return cannot be done using the original payment method, or the merchant’s return policy does not allow the full refund. Store Credit essentially transforms return to exchange, so the merchant does not lose the customer and associated revenue.

Store Credit Token can be linked to the item price in local fiat currency, so the customer can use those tokens during next purchase “instead” of or in addition to the payment with local fiat currency. Store Credit tokens usually either do not expire or have very distant expiration date as they are basically replace the fiat currency.

Loyalty Rewards

Loyalty Rewards is powerful marketing instrument which attracts customers and increases spending. Loyalty Rewards can be awarded with each purchase, or as one-time bonus, or using other models. The rewards than can be used to makes purchases of particular items or all items, or converted to cash. Loyalty Rewards are not necessarily linked directly to fiat or crypto currency as they can be spend to provide discount or buy a special “unique” reward items that are not available for sale using other methods of payment.

Loyalty Rewards usually have relatively close expiration date. This way the merchant “stimulates” earning more rewards and eliminates accumulation of very large amounts of reward points that can become useless.

GIft Certificates

Gift Certificates can be issued by merchant in order to attract customers. In order to increase the effect, gift certificates can be sold with discount (for less than their nominal price). Gift Certificate tokens usually either do not expire or have very distant expiration date as they are basically represent the fiat currency.

Discount Coupons

Discount coupons can be used for one-time or long term promotions. The coupons can be distributed publicly or to individuals, in wallet or paper form. The coupon then can be scanned by point of sale in order to get discounted or even free item.

Transactions with Merchant Tokens

Create

Creating new merchant token (“smart contract”). Can be done using point of sale app.

Renew

Renew merchant token (“smart contract”). Can be done using point of sale app.

Add

Add more merchant tokens to the circulation.

Issue

Merchant’s point of sale sends merchant tokens to the customer wallet or prints a paper wallet.

Redeem

Customer redeems merchant tokens at merchant’s point of sale using wallet app or paper wallet.

Merchant Token Fees

All the merchant token fees are paid to the current supernode authorization sample.

Merchant Token Transaction Fees

Merchant always pays the token transaction fee, which means the buyer never pays the fee. A regular transaction fee is applied to each transaction with merchant token, including adding, issuing, and redemption. As GRAFT fees are proportional to transaction amount, the fee is calculated based on 1 token = 1 GRF, although it’s not necessarily that the token has any direct link to the GRF or other currency. It’s important to note that GRAFT fees are calculated based on logarithmical formula so there is no danger of paying high fee on large amounts.

Initialization and Renewal Fees

The initial Create transaction implies a special higher fee because it is associated with naming a token. In order to prevent “domain squatting”, the initial fee is set to a reasonable amount that prevents massive abuse. Initialization fee of 5 GRF is required to generate a new merchant token smart contract (Create transaction). The renewal fee is 10 GRF.

VChain

VChain allows creating a virtual chain of stores so multiple point of sales can be “connected’ to the same private “virtual blockchain”. Thus, there is a dual meaning of word “Vchain”: virtual chain and virtual blockchain. Vchain creates a private common platform for managing merchant tokens and items catalogue.

Merchants can create their own private vchain which is going to be accessible only by this particular merchant and contain all information about its tokens. Vchain allows connecting multiple points of sale or even creating a chain of multiple stores. Points of sale that belong to the same vchain can issue and accept the same merchant tokens, use the same shared item catalog stored and maintained on the blockchain, generate aggregated transaction reports, and more.

Buyers can use vchain to link multiple wallets so they can manage multiple accounts and move funds between those accounts without paying fees. This feature is useful for family and corporate accounts.

VChain Fees

There is initialization annual fee of 5 GRF for creating a new Vchain smart contract. The renewal fee is 10 GRF. Those fees are required to securely process the smart contract and prevent system abuse. There is a separate annual fee of 10 GRF for adding another point of sale or wallet to the vchain.

All vchain fees are paid to the current supernode authorization sample.