How is Graft real-time authorization (“instant confirmation”) within a few seconds possible with 2 minute block interval?

Unlike most crypto payment systems, and similar to traditional credit/debit card processing, Graft payment is divided into two phases: authorization and settlement. Like in credit/debit card world, Graft authorization happens in real time (hundreds milliseconds to a few seconds, depending on various conditions), while settlement is performed later on, usually within 2 minutes (compare to several hours and even days in traditional payment networks).
Although there are cryptocurrencies with block (settlement) interval less than 2 minutes, there is no specific reason to reduce it, especially with Graft built in “always on” real time authorization system. First, very short interval complicates the block generation and PoW process, as a lot of supernodes must communicate each other and agree on the new block, so with very short interval the network latency will start affecting the process. Second, reducing the interval still does not resolve the real-time authorization (“instant confirmation”) problem. Even with 30 seconds interval, it is still too long for real time payments (credit card authorizations are in a range of hundreds milliseconds to a few seconds), not to mention the fact that 1 confirmation (1 block) is still not enough to mitigate the risk of fork for significant amounts. So special additional technology is still required to resolve the real-time authorization problem. Graft resolves this problem by implementing a scheme called authorization sample, which is a group of supernodes that is selected by special Proof of Work/Proof of Stake algorithm from a larger pool of candidates.
The supernodes in authorization sample must match several criteria in order to prove their loyalty to the network:
Must be an active miner – solve at least one block within last 1440 blocksMust maintain a collateral (“stake”) deposit account with 1000 graftMust be “always on” (99% of the time within last 48 hours)Must have a public IP
The authorization sample supernodes validate the transaction and guarantee that the buyer cannot spend the same money more than once until the transaction is settled (added into the block which is written into the blockchain). The settlement is performed by the mining part of the supernode within 2 minutes.

How are decentralized credit card payments possible given the amount of regulations and technical limitations?

Traditional credit and debit cards are accepted by service brokers which are hosted by Graft supernodes as network “plugins”. The supernode network is fully decentralized organization. The service broker, including credit card acceptance broker, is a distributed gateway which has an owner who complies with all necessary regulations. In addition to default “reference” implementation of credit card acceptance broker created and maintained by Graft Foundation, there will be multiple third party implementations that offer similar competitive services. Thus, technically, a single credit card acceptance broker is not fully decentralized service but it is running on decentralized, distributed, and diverse service platform.  In addition to traditional credit and debit cards, Graft is designing and implementing its own crowdfunded credit card eco-system which will be fully decentralized.

Is Graft mineable?

Yes, Graft is mineable. Unlike most cryptocurrencies, Graft consists of supernodes that process two-phase payment transaction, just like “traditional” credit card payments: real time authorization and settlement (mining). Also, supernodes may host additional brokerage services such as credit card authorizations, instant exchanges, and merchant payouts. Supernodes receive mining reward for each solved block, but they do not earn transaction fees from mining. Transaction fees can be earned by processing real time transaction approvals. Supernode is allowed to participate in real time authorization process only after successfully solving a new block.

How is Graft different from Dash?

There are several major differences between Graft and Dash, but all of them are focused on the Graft’s mission to be as close as possible to the “real world” of retail, hospitality, gas stations, convenience store, or restaurant payments.
Dash’s InstandSend is an optional feature, which is implemented on top of the blockchain network protocol as a 2nd application tier. Therefore, Dash transaction can be processed in two ways: InstantSend authorization or “regular” send. If InstantSend fails for any reason, transaction is sent through the regular slow path. Such a scheme is not acceptable in the “real world” of payments. In order to “compete” with the dominance of credit cards, crypto payments must be always approved instantly. Unlike Dash, Graft real time authorization is a built-in feature: all Graft transactions are approved in real time, within a range between several milliseconds to a few seconds, depending on the merchant settings. Thus, both online and brick-and-mortar merchants and their customers can always rely on Graft real time authorization. The buyer is required to pay an additional fee in order to process the payment faster using InstantSend. Graft transaction is always approved in real time, and such approval does not require any additional fee. A small symbolic flat fee is paid by the merchant (similar to the credit card fee in the “real world” but significantly lower), which enables an an adoption of Graft for micropayments. Like in the world of traditional payments with credit and debit cards, the buyer (sender) does not care about the fee rate or complexity of the fee structure, which allows much higher conversion rates and better buying experience.  Dash has another optional feature called PrivateSend which also requires additional configuration efforts and extra fees from the sender (buyer). Unlike Dash, which is based on Bitcoin code, Graft is based on CryptoNote protocol and Monero code, which provides incomparably higher level of privacy, untraceability, and unlinkability of transactions, right “out of the box”, without any additional actions or fees required from either buyer or merchant. Thus, each payment on Graft network is “visible” only to the buyer and merchant involved in this particular payment, just like in the real world of credit card payments, or in fact even better as there is no central authority in between.   Unlike Dash, which is mainly a cryptocurrency with some optional features, Graft is an open payment platform that allows merchants to accept various methods of payments such as other cryptocurrencies and credit/debit cards. Different merchant payout options in altcoins of local fiat currencies will be also available through Graft point of sale app and Graft service brokers. Graft wallet users can also instantly exchange other cryptocurrencies or fiat currencies as part of the payment transaction.Graft payment processing flows and transaction types are atypical for cryptocurrencies but very usual for the brick-and-mortar and ecommerce merchants; those flows have been designed to allow an easier adoption by the mainstream merchants and consumers, without the need for any centralized intermediaries (payment processors) which defeat the basic principle of cryptocurrencies – decentralization. Unlike other cryptocurrencies that provide a single wallet app, which is typically used for both sending and receiving payments, Graft separates those functions, just like in the “real world”, between buyer’s wallet app and merchant’s point of sale app. So the users with different interests will never be confused by the “opposite” features they never use, such as top up in the wallet or payout in the point of sale. And finally, the network of Dash masternodes is based on Proof of Stake, while Dash miners still use Proof of Work. The owner of each masternode is required to pledge 1000 coins (~ $200,000) in order to be able to perform InstantSend or PrivateSend. Unlike Dash, all Graft network nodes are both instant authorizers and miners, and so they earn their right to issue real time payment approvals by successfully mining blocks. Thus, both real time authorization and mining are enabled by Proof of Work, which makes the whole system more fair and secure.

Check out Graft FAQs page to find answers to most important questions about new crypto payment network

Graft FAQs:
– Is Graft a cryptocurrency or decentralized point of sale system? – How is Graft real-time (“instant”) authorization within a few seconds possible with 2 minute block interval? – It looks like in order to process real-time authorization Graft needs to put a “lock” on buyer’s account. How does it not violate one of the main goals of any cryptocurrency system – untraceability? – Has the Graft team ever considered using Ripple transaction protocol as an underlying blockchain settlement mechanism? – Graft mobile wallet and point of sale do not contain the full copy of the blockchain for obvious reasons. Does it mean the wallet content is stored on supernodes which may compromise its security and privacy? – Is the Graft supernode sample authorization scheme similar to Ripple’s consensus process?
– How Graft is different from Dash?

First set of SuperNode API’s is up, POS and Wallet App development begins

It’s been a very busy few days!  The progress has been outstanding however!  We have first pass on the SuperNode complete and API’s are ready for mobile developers to integrate with!!
Meanwhile we’ve been working on designing the apps wireframes and workflows, iteration after iteration.  The goal is to have a super simple but functional POS app and the same for the wallet.  Here’s what we have so far:
 Just got out of the meeting with mobile developers where we flushed out final set of details, ready to get to work!  ETA 14 days.  How’s that for speed to market? 🙂

New version of Graft white paper reveals more details about the Graft real time transaction authorization protocol

New version 1.1 of Graft white paper has been released on Github. The updated white paper reveals more details about the Graft real time transaction approvals and other payment platform features.
Changes since the last version:
  • Relay supernode definition
  • Additional details about real time authorization mechanism
  • Authorization sample definition
  • authorization sample selection algorithm
  • Supernode Rewards
  • Decentralzied crowdfunded credit cards
  • Merchant (domain) tokens
Graft: Decentralized, Real-time Credit, Debit, and Crypto Payment Processing Network.

We’re off to the races!

Happy to announce that yesterday we’ve completed first step (in series of many) – we have successfully forked and compiled Monero blockchain, and generated a genesis block!!!!
We’re talking Proof of Concept and the test network at this point, but this was a critical step in figuring out whether we’d be able to use Monero as the basis for Graft and it looks like we’re clear!
Houston, we’re go for launch!

How crypto payments are infiltrating the $60bn global art market

Cryptocurrencies are entering mainstream merchants slowly but surly.
Eleesa Dadiani owns and runs an art gallery in London’s famous Cork Street.
In a first for the tradition-bound art world of Cork Street, her international clientele will have the opportunity to pay using Bitcoin, the digital cryptocurrency underpinned by blockchain technology.The gallery will also accept other cryptocurrencies such as Ethereum, Ethereum Classic, Dash, Litecoin, and soon, Monero.

Merchant Tokens

One of the most interesting things that modern blockchains do well and Graft will take full advantage of is building multi-level currencies with help of smart contracts.  These domain specific currency derivatives (tokens) fit naturally with the merchant business of promoting loyalty, stimulating repeat business, and enabling suppliers.  With that I’d like to look at adding this new section to the white paper:
Merchant (Domain) Tokens
In addition to fast and inexpensive transactions, merchants place high value on customer loyalty and branding.
This functionality is enabled by the token layer of the Graft currency.  The token represents domain (merchant) specific Graft use, and offers smart-contracts backed functionality like loyalty point accumulation and use, reward points, sale discounts, spending discounts, competitor discounts, coupons, etc.
A coffee chain for example could create a merchant token and attach promotion rules that would provide a patron ability to get discounts on iced drinks at given time of the day, it would tally the purchases with the establishment and offer rewards based on activity or non-activity.
Finally, Graft Domain Tokens would provide a very efficient mechanism for couponing by allowing the merchants to open up the coupon creation and assignment rules within their domain network.