By Matheus Darós Pagani
CEO of 4CADIA Foundation
The application concept arose based on codes that are run on the equipment in the user’s own possession (client side), such as handheld calculators or cameras. With the advent of computers, these applications have maintained this feature for a long time.
From the Internet, the processing of some applications migrated to servers and data-centers, which process the information on dedicated infrastructures(server side) and provide access to the end user through specific “clients” or even web pages. These are the so-called centralized applications.
The next step in this evolutionary path are the decentralized applications, in which there is no central owner or controller. They work by simultaneous operation of multiple owners or controllers (nodes or peers), each of which normally stores a copy of the system’s resources and data.
This decentralization makes applications less prone to failure, as resources remain active as long as at least one of the nodes or peers continues to operate. Therefore, there is a possibility of repairing the system or troubleshooting while it continues to function normally.
It is common for these applications to operate with open source. Many of them also operate with consensus mechanisms, including some form of compensation and governance for the various controllers to keep the system in operation.
Most famous decentralized applications
- Torrent is perhaps the best known example of a decentralized application, a connection protocol that accelerated and simplified the task of transferring files via the Internet, without the need for a central server distributing the files. Performing a conventional download requires connection to a server, requesting a copy of the file stored there. In the Torrent protocol, the transfer is directed by a tracker to other machines around the world that have the complete files (seeds) or parts of them (peers). All network participants do both download and upload functions simultaneously.
- PopCornTime, a streaming platform like Netflix, but which does not have a single server or central controller. Users who make content available by uploading data are rewarded by the network with a faster download speed.
- Open Bazaar is an open source project that develops a protocol for e-commerce transactions in a completely decentralized marketplace, where payments are made through cryptocurrencies. Transactions between them are built as Ricardian contracts and each step of the exchange is signed cryptographically. Custody takes place through a system of multiple signatures, with the possibility of arbitration by a third party.
Blockchain, decentralized and distributed applications
Decentralized applications, despite the advantages, sometimes still have problems similar to centralized ones, as servers and users find the same exposure to individualized attacks.
Blockchain is a type of decentralized application that compensates for many of these flaws by its distributed character. The decentralized peer-to-peer network works like an open and distributed ledger, cryptographically managed, using various protocols and consensus agreements among its peers.
Shared on a public or private computer network, each point on the network keeps a copy of the ledger, so that there is no single point of failure. All information is mathematically encrypted and added as a new block to the historical record chain.
Consensus protocols are used to validate a new block or set of transactions with other participants before it can be added to the chain. This avoids fraud or double spending without requiring a central authority. The ledger can also be programmed with “smart contracts,” a set of conditions recorded in the blockchain, so that transactions are triggered automatically when conditions are met.
Bitcoin
The most famous example of blockchain use is Bitcoin. It is a digital currency, which is not regulated by any central bank. Bitcoin transactions consist of registering incoming and outgoing currencies. The records of the transactions are stored in blocks, with each new block linking to the previous one in an interdependent chain. The currencies, in limited numbers, are mined by network users who receive rewards to solve highly complex computational problems. As an example of OpenBazaar, Bitcoin can operate as transaction currency in a decentralized application. However, storing large amounts of data is complicated and does not fit well with decentralized computing.
Ethereum
Ethereum, another digital currency, has as its principle to bring blockchain technology and smart contracts to everything that can be programmed. The transaction records are stored in a kind of public, distributed and secure spreadsheet guaranteed by encryption. Intelligent contracts “signed” in the Ethereum blockchain and mining are paid in ether, the platform’s fuel.
Ethereum is the first major blockchain for decentralized applications. Ethereum Virtual Machine (EVM), the main technology of the application, allows to simulate and run any computational algorithm. A piece of code that runs in this environment is called a smart contract.
These smart contracts can be interacted programmatically, or through a specific user interface. The dApp term refers to a set of smart contracts, with a Frontend interface, that can provide user features, acting as a common application, but the logic and data management is built upon smart contracts.
Since the birth of Ethereum, more than a thousand dApps have been created for many industries. Check out our previous articles to know more about some of these dApp applications.
Other blockchains for dApps
Many other blockchains provide support for building Smart Contracts and dApps. Most of them differ on how they tackle on the scalability dilemma. It is even possible to exchange information and tokens between those different blockchains using Cross Chain communication solutions.
Also check out our previous articles to learn more about blockchain applications in areas such as:
- Digital identification
- Elections
- Land registration
- Education
- Health data
- Drug industry
- Food market
- Sustainability
What would be the future of dApps and the blockchains that follow its support? What are the upcoming trends for disruptive solutions built using dApps? Stay tuned to know more on the next articles.
If you like the article, clap your hands on the side.
