Key knowledge points of bsn-ddc basic network (IV) generation and management of DDC



Official account: BSN Institute

On January 25, 2022, the blockchain service network development alliance (BSN Alliance for short) launched the “bsn-ddc basic network” and entered the trial commercial stage. At the same time, the bsn-ddc official website portal ( was launched for ddc/nft business parties to apply for the registration of “platform parties”. The launch of bsn-ddc will provide infrastructure capacity support for the landing of NFT technology in China and escort its compliance development.

Why does bsn-ddc play such a big role?

In order to facilitate developers to have a comprehensive and in-depth understanding of bsn-ddc, BSN Institute launched a series of interpretation of key knowledge points of bsn-ddc basic network. Bsn-ddc is comprehensively and deeply introduced from the aspects of background, platform party joining, accessing DDC network, DDC generation and management, and basic network cross chain mechanism.

This issue is the fourth in a series of articles on DDC generation and management.

1. BSN official DDC

The BSN official DDC refers to the official DDC generated through the BSN official DDC contract deployed by the BSN alliance. The BSN alliance has launched a set of official DDC contracts with the same functions but different implementation processes for each open alliance chain. Each official DDC on the same chain is generated from this official DDC contract and endorsed by the BSN alliance.

The official DDC contracts of BSN on all DDC open alliance chains are open source on GitHub.

The platform party can download and view by itself, and can design and develop its own DDC contract by referring to the official DDC contract.

1.1 BSN official contract function design description

The official DDC contract can be divided into three parts: billing contract, permission contract and master contract. Each part consists of agency contract and business contract. The billing contract is mainly used to maintain and manage the service fees required for each official DDC service; The permission contract stores and verifies the permissions of each chain account in the role-based permission management mode; The master contract mainly implements the official DDC business, supports the erc721 standard and erc1155 standard, and adds the BSN alliance’s supervision and execution function that can freeze and unfreeze DDC according to the requirements of the regulatory authorities.

The following are the main functions in the official DDC contract:
Key knowledge points of bsn-ddc basic network (IV) generation and management of DDC
1.2 official DDC contract call

The platform party can call the official DDC contract in two ways:

[direct call]

It refers to the process that the business system of the platform party directly calls the official DDC contract. The platform party can call the contract method through the official DDC SDK; You can also implement chain transaction encapsulation by yourself according to the gateway access instructions of the corresponding open alliance chain, and call the official DDC contract method through the gateway.

[call through business contract]

It refers to the process that the platform party develops and deploys the service contract in the DDC network by itself, and invokes the official DDC contract through the service contract in its business system. The platform party can expand the DDC based application layer business processing in the business contract according to its own business needs, and provide users with more transparent and trustless blockchain applications based on the DDC network.

1.3 description of official DDC service fee

Invoking the official DDC contract involves the energy consumption cost of chain transaction and the official DDC service fee.

[energy consumption]

The energy consumption fee is jointly defined by BSN alliance and the chain technical party, and the unit is “energy value”. According to the computing power and storage resources consumed during transaction processing, the corresponding energy value is deducted from the chain account that initiated the transaction. The transaction fee required for official DDC business processing on each open alliance chain is converted into RMB about 0.03-0.07 yuan per transaction (each chain will be slightly different), and the actual amount will fluctuate with the chain computing power and resources consumed by the transaction.

[official DDC service fee]

The official DDC service fee is defined and charged by BSN alliance, and the unit is “Yuan”. The service fees corresponding to different service methods of the official DDC contract deployed on each open alliance chain are as follows:

Official DDC generation, 1 yuan / transaction (Note: it is also 1 yuan if multiple copies are generated through a single transaction of erc1155 standard.)

Official DDC circulation and destruction, 0.3 yuan / transaction

2. the platform party deploys the ddc/nft contract by itself

The platform party can choose whether to use the official DDC contract to generate and manage DDC, or deploy its own ddc/nft contract. The official DDC contract code will be open source and continuously maintained and updated. The platform party can use the official DDC contract or make customized modifications on its basis and deploy it into its own ddc/nft contract.

The platform party only needs to pay the energy consumption cost for deploying and invoking its own ddc/nft contract. The energy consumption required for deploying the contract is related to the size of the contract. The energy consumption required for invoking the contract is related to the online computing power and storage resources consumed by the contract logic processing of each DDC open alliance chain. The cost of each transaction is about 0.03-0.07 yuan.

3. ddc/nft metadata storage

Metadata is the data that describes the detailed attribute information of ddc/nft. It can be a picture, a video or a group of structural data. Due to the transaction processing performance and storage bottleneck of the blockchain network, ddc/nft metadata with a large amount of data is not suitable for processing and storage on the chain. It often needs to use other tamper proof off chain storage solutions to store it, and the ddc/nft contains URI links and metadata digital summaries pointing to the metadata. When generating ddc/nft, the platform party can choose to store its metadata in the IPFs proprietary network provided by the BSN blockchain service network. The platform party can also store ddc/nft metadata in its own business system or based on third-party storage services (such as AWS S3 cloud storage).

BSN IPFs VPC is a service gateway that provides IPFs native service interface for blockchain applications based on the IPFs distributed file storage private network deployed in each virtual data center of BSN.