Introduction¶
The purpose of the Overview manual section is to:
Introduce you to the importance and problems of multi-party applications.
Provide a high-level overview of how Canton can help you build and run multi-party applications.
Explain the different components of the Canton ecosystem and how they fit together.
Show how the different products of Digital Asset allow you to join the Canton Network as a user or a provider of services.
Multi-party applications¶
Software applications are used every day to facilitate communication, share information, and support decision-making. But what happens when you need to collaborate with multiple parties on the same set of data? How do you ensure that everyone has access and can operate on the same information? Who controls the data? Who controls who can collaborate? When there’s trust and collaboration within the same organization, responsibility is often delegated to a central authority operating a centralised application, such as the IT department of our company or one of the large cloud providers. But what if you are not part of the same organization? What if you cannot agree on who should operate the application? What if you do not trust each other but still want to collaborate?
Originally, these problems are solved by defining a common protocol and having each party implementing their own version of the application, exchanging messages to signal data changes. Such applications are very bilateral in nature and require a lot of coordination between the parties to keep the implementations and the data in sync. These technical challenges impact the efficiency and the business value, leading to high cost, low flexibility and long lead times. Well known examples of such applications can be found in the financial markets or in the health care sector, requiring large and well-funded organizations that can afford to build and maintain them.
Technically, the problem can be stated as follows: how do you coordinate reads and writes across multiple databases of multiple, potentially unknown parties who do not trust each other nor a central authority, but with the strong guarantee that the data is always correct and consistent, and only accessed and modified according to the individually pre-agreed rules for the given data set?
An application built with such a technology provides both: the individual control and data sovereignty of each party, while at the same time guaranteeing tight integration and collaboration between the parties. Such applications are called multi-party applications. Enabling such applications is the problem that Canton solves out of the box, creating a network of self-sovereign, tightly-coupled, multi-party applications built for seamless real-world business success: the Canton Network.
Continue diving into Multi-Party Applications in the respective section of the manual.
Ledger properties¶
In order to solve the problem of complex, real-world multi-party applications, Canton is designed to provide the following properties:
Privacy: The data is only visible to the parties that are allowed to see it. No one else can access it.
Integrity: The data is always correct and consistent. No one can change it in a way that would violate the pre-agreed rules.
App Composability: The applications can unilaterally be composed together to create new applications. This allows to build complex applications that are built on top of existing ones, but in a way that does not impact existing users.
Network Composability and Horizontal Scalability: The network can be extended by adding new validators and synchronizers, such that the network can be extended unilaterally and scaled horizontally. It still remains a single network of networks.
Regulatory Compliance: The data is shared, stored and operated by the parties owning it. This allows to comply with existing regulations of the jurisdictions where the parties operate.
Continue diving into the Canton requirements and learn more about how Canton is different from other ledgers.
Elements of the Canton Network¶
The Canton Network is the union of all applications and users that are built and operated using the software Canton, which connects individual instances through the Canton Protocol.
The shared data items managed and synchronized by Canton are called contract instances. Every contract instance is associated with a template that defines the smart contract choices for the contract instance. These choices represent the possible update commands on the ledger, archiving a given set of contracts and creating new ones atomically. These rules are written in the Daml programming language and contain the business logic and authorization rules.
The entirety of the contract instances and templates is called the Ledger. Each contract is owned by a group of stakeholders, called Parties. Each party participates in the network through their validator node. This validator node has only visibility into the subset of contracts of the parties associated. As validator nodes are able to connect to different networks, the entire network forms a single Virtual Global Ledger which is not controlled by any single entity.
The software Canton has two infrastructure components: Synchronizers and Validators (formerly named participants). Validators process and validate transactions, managing the ledger state of their parties. Validators do not expose any public port, but instead connect to synchronizers to form a network with other validators. Each validator can connect to multiple synchronizers unilaterally, creating a network of networks.
In order to transact with each other on a given transaction, validators need to find at least one synchronizer where they are all connected to. This synchronizer will then order, buffer and forward the encrypted messages to the respective validators without understanding what is being transacted on. There is one specific instance of a synchronizer that is called the Global Synchronizer (https://sync.global), serving as the global backbone of the network.
Contracts are not tied to synchronizers. Synchronizers are not aware of each other. Instead, validators can use any suitable synchronizer for their transactions, creating an natively interoperable network of synchronizers and validators. This allows the Canton Network to scale horizontally by just adding more synchronizers and validators whenever needed.
Continue diving into the elements of the Canton Network.
Ledger concepts expressed in database terms¶
The concepts can be related to databases: templates are table schemas, contract instances are table rows, choices are stored procedures performing a set of atomic delete and insert statements. But instead of running against a single database, different actors on the network now exchange which stored procedures they want to run through the Canton protocol. The protocol orders, validates, removes conflicts and distributes these requests to the affected parties such that they can apply it to their local data stores deterministically.
Join the Canton Network¶
In the Canton Network, you can either be a user, an application provider, or an infrastructure operator. Digital Asset provides a set of products and services that allow you to join the Canton Network conveniently and easily.
Build your own applications using our SDK.
Use our financial application building blocks to accelerate the development of your own applications.
Run your own validator node as part of an existing network.
Create your own sub-network by deploying your own synchronizer.
Read more about the different ways to join the Canton Network in the How to Engage with the Network section.