Goopal White Paper

Digital Point Based on Blockchain Technology

November 2015

Table of Contents
  • Goopal White Paper 1
I. Overview 2
  • 1. What is Goopal? 2
  • 2. Objective 3
II. Goopal Technical Principle 3
  • 1. Blockchain Technology 3
  • 2. Data Structure of Blockchain 4
  • 3. Encryption and Decryption of Block 5
  • 4. NTP Time Synchronisation 5
  • 5. Principles of Communication 6
  • 6. Working Principle of POW and DPOS 6
III. Goopal Issue Principle 7
IV. Goopal Transaction Principle 8
V. Security Guarantee of Goopal 10
VI. Conclusion 11

I. Overview

1. What is Goopal?

Goopal is a global mobile digital point system, which develops based on blockchain technology. The decentration of blockchain technology endows fairness, openness and transparency on Goopal, which makes Goopal technology applicable to wide-ranging applications.

2. Objective

Drive Goopal to become freely shared around the world-establish a globally decentralised digital point service system through the widespread application of Goopal technology; Benefit every Goopal user with an efficient, convenient and safe technology service; Make Goopal technology forge out a future with infinite imagination by supporting open sources to the developer.

II. Goopal Technical Principle
Goopal mainly adopts, inter alia, the technology of blockchain, NTP time synchronisation, encrypted P2P networking, POW&DPOS and the blockchain is the core technology used by Goopal.

1. Blockchain Technology

Blockchain is a data structure for organising and maintaining a large quantity of data in a method of decentration based on cryptography technology. The blockchain is especially applicable to the accounting books of data assets. Data in the blockchain is allocated a related data signature that cannot be forged.

A complete blockchain includes all legal blocks currently available. The blockchain means Goopal generates a block about every 10 seconds. The generation of each block relies on the hash value of the previous block, which means data on all previous blocks must be changed if you intend to tamper with the content of a block, so that it is virtually impossible to tamper with the blockchain.

2. Data Structure of Blockchain

The block is divided into two parts, HEADER and BODY, as shown in Figure 1.

3. Encryption and Decryption of Block

The block includes the signatures of delegates for this block, and the signature is encrypted by public-private key pairs provided by the ECC encryption algorithm. The delegate signs for the block end with a self-owned private key and stores the signature in the delegate signature area, and then the receiver decodes it using the public key of the delegate. If the decoding fails, the block will be abandoned, and meanwhile the legal transaction in this block will be repackaged.

4. NTP Time Synchronisation

NTP is a protocol for synchronising the time, which can synchronise the machine with the clock source (e.g. quartz clock, time server, etc.) and provide time correction with high precision (the time error between the local network and standard time is less than 1ms, and that between the wide work area and standard time is less than several tens of milliseconds). It can prevent malicious protocol attacks by encryption as well. The NTP time server can ensure that the time among delegates is synchronised to ensure the block generation sequence of delegates themselves.

5. Principles of Communication

The communication of the Goopal system is based on the P2P (Peer-to-peer) network, which is a distributed application architecture allocating tasks to multiple nodes. Each node is an equal participant during the whole application.   In the traditional C/S architecture, the server generally provides services and the client uses the services. The normal operation absolutely relies on the stability of the centralised server. While in the P2P network, the node directly provides its resources (e.g. computational capability, disk space, network bandwidth) to other nodes, and the centralised server becomes redundant. The node is both a provider as well as a user of resources. Goopal system realises an encrypted transmission protocol based on the TCP protocol. After the TCP connection among nodes is established, the interconnected nodes will create their own key pairs respectively, and send the public key to the other node for generating a transmission key that will be used to encrypt the communication. The user can set its own seed node, or use the default seed code of the system configuration. After the wallet starts up, it will establish connections with the seed node and historical node. After establishing a connection, they will exchange their addresses on the connected node to construct and expand the whole P2P network.

6. Working Principle of POW and DPOS

POW (Proof of Work) is the block generation mechanism adopted by Goopal during the distribution stage. The system will provide a target hash value while calculating the hash value provided by the calculating participants, and then make a comparison between the two values. If the hash value of this block is less than the target hash value, the block meets the necessary requirements. This is to utilise the irreversibility of hash algorithm and the randomness of results to ensure that only the participants can get the block generation award by competition of computational capacity, which keeps the fairness of integrity of the system. DPOS (Delegated Proof-of-Stake) is the block generation mechanism adopted by Goopal during the operational stage. Compared to POW, it can offset the negative effect generated by the centralisation by the technology-based democracy while solving the problems of waste and low-efficient block generation, which is more aligned with the mechanism of the financial system. Goopal system chooses the top 99 delegates based on the voting results in the transaction, and its working content is to package the generated blocks of transactions. DPOS makes the network more democratic than other systems by using the voting procedure for decentralisation.

III. Goopal Issue Principle

The publication of Goopal adopts the POW mechanism and then the DPOS mechanism. The application of the POW mechanism in the early stage ensures the fairness of the user's participation. The DPOS mechanism later authorises the dependable delegate to generate blocks, which improves the efficiency of the whole system on the premise of fairness and transparency. It conforms to the existing financial system and the settlement will be faster and more convenient.

Figure 2 Sketch Map of Operating Principle

The initial digital point in the operating stage comes from the snapshot of the digital point at the end of the distribution stage, so Goopal system combines the advantages of the two stages.

IV. Goopal Transaction Principle

What Goopal maintains is an open and queriable blockchain system of the whole network; therefore the quantity of digital point owned by a user is calculated out from the consensus network. The operation for digital point is called a transaction. In the system, every user saves all transaction data.

Figure 3 Sketch Map of Transaction Network

As shown in the above figure, the role of ordinary user is to transmit messages from other users, receive the packaged blocks sent by the delegate users and charge the transactions to an account. In addition to undertaking the responsibilities of the ordinary user, the delegate user needs to verify the digital signature of every transaction and check whether the procedural fee is sufficient.

Of course, the delegate users will get a certain digital point as an award for each generated block in consideration of the greater responsibilities taken by them.

When user A intends to give his or her own point to user B, user A will broadcast the transaction to the whole blockchain network, and the broadcast includes:

1).The quantity of transferred digital point;

2).Transferred-in user B;

3).Digital signature of transferred-out user A.

After the transaction is broadcast to the network, the delegate will verify the legality of this transaction. The so-called legality includes:

1).Whether user A has enough digital point;

2).Whether the digital signature of user A is valid.

Verify the legality of the transaction again when the delegate generates a block. The legal transaction will be packaged with the block and it will then be broadcasted to the whole network.

Other users verify whether the digital signature of the user who generated this block is legal. If the signature is legal, update the quantity of digital point of user B.

V. Security Guarantee of Goopal

1. Characteristics of decentralisation

All nodes have a complete data backup, which ensures the transparency, fairness and security of the system. Even if most nodal data are damaged, the data can be synchronised via the rest of the node, which makes the system more stable.

2. Guarantee of blockchain technology

Guarantee the uniqueness and prevent alteration of the blockchain and ensure that the forged transaction and block will not be recognised by the system.

3. Supervisory mechanism for election of assignee

The delegates creating the block are elected by users of the whole network under the supervision of the whole network. Ensure the fairness and reliability of the delegates.

4. Cryptographic algorithm of ECC

Adopt mapping authentication mechanism of elliptical curve. The difficulty in decoding the algorithm is proved to be exponential, which makes it impossible to decode the private key.

VI. Conclusion
This is an open-source project by reason that the global network hasn't any central control nodes, and it can make payment to any corner of the world for a low transaction fee. Its transaction confirmation is faster and it has higher network transaction volume and efficiency. The prudent cryptographic protocol makes the network system fully ensure the informational security of every user. Goopal system can be applied in many occasions in the future, from online to offline, from traditional industry to the internet industry and so forth. Its sufficient liquidity is enough to prove the maturity, security and stability of the system.