Decentralized Applications Architecture: Wallet, Frontend, Backend & Smart Contract

Summary

In this video, the different architectures of decentralized applications (DApps) on Ethereum are explored. The core building blocks include smart contracts, wallets, and user interfaces. The video covers five key architectures: Pure Decentralization (using IPFS), Common DApps with centralized frontends, Backend with transaction broadcasting, Backend with signature-based transactions, and Backend with a centralized wallet. Each approach has its own trade-offs between decentralization, user experience, and security. The video concludes by asking viewers which architecture they’ve used or would like to try, encouraging engagement and discussion.

Takeaways

• 😀 Smart contracts on the blockchain are the core of decentralized applications (DApps), processing all valuable data and transactions.
• 😀 Users interact with DApps through wallets, which store private keys used to send transactions to smart contracts.
• 😀 The front-end user interface (UI) of DApps can be a web or mobile application that allows users to interact with smart contracts in a user-friendly way.
• 😀 The 'Pure DApp' architecture is the most decentralized, where both the smart contract and the front-end are served from decentralized platforms like IPFS.
• 😀 The 'Common DApp' architecture is the most common, with a decentralized smart contract but a front-end served from a centralized server, leading to potential vulnerabilities.
• 😀 In the 'Backend + Broadcast Transaction' architecture, users send transactions to a backend server, which validates and broadcasts them to the blockchain, reducing the decentralization of the DApp.
• 😀 The 'Backend + Signature' architecture allows users to sign transaction messages and send them to the backend, where the backend broadcasts the transaction, while ensuring security through signature validation.
• 😀 The 'Backend + Centralized Wallet' architecture requires no front-end wallet for users, as all interactions are handled through a backend system that uses its own private keys to sign transactions on behalf of users.
• 😀 While the 'Backend + Signature' and 'Backend + Centralized Wallet' architectures are less decentralized, they provide easier onboarding for users and can reduce friction in interacting with blockchain applications.
• 😀 The trade-off between decentralization and practicality is a recurring theme in DApp architecture, with some compromises made to improve user experience or application performance.

Q & A

What are the basic building blocks of a decentralized application (dApp)?

The basic building blocks of a decentralized application (dApp) include the smart contract on the blockchain, a wallet to store private keys for transaction signing, and a front-end UI (web or mobile) that allows users to interact with the smart contract.

What does the 'Pure dApp Architecture' entail?

The 'Pure dApp Architecture' is the most decentralized setup where the smart contract is on the blockchain, and the front-end is hosted on a decentralized file system like IPFS. This ensures the entire system is decentralized, making it resistant to attacks on centralized servers.

Why are few dApps using the Pure dApp Architecture?

Few dApps use the Pure dApp Architecture because using IPFS for hosting the front-end can be more complex, even though it offers maximum decentralization and security.

What is the common dApp Architecture, and how does it differ from the Pure dApp Architecture?

The common dApp Architecture involves a decentralized smart contract on the blockchain, but the front-end is hosted on a centralized server. This introduces vulnerability as centralized servers can be hacked or restricted, unlike the Pure dApp Architecture, which is fully decentralized.

What are the potential risks of using the common dApp Architecture?

The main risk of the common dApp Architecture is that if the centralized server hosting the front-end is compromised, the dApp may become inaccessible or vulnerable to attacks. However, the decentralized smart contract remains secure.

What does the 'Back-end + Broadcast Transaction' architecture involve?

In the 'Back-end + Broadcast Transaction' architecture, users send transactions to a backend server rather than directly to the blockchain. The backend verifies and broadcasts the transaction to the Ethereum network, offering added control over transaction validation but also introducing a layer of centralization.

What are the benefits and drawbacks of using the 'Back-end + Broadcast Transaction' architecture?

The benefit of this architecture is that it helps protect users from making mistakes in their transactions. The drawback is that it centralizes control in the backend, so if the backend is compromised, the dApp could be at risk. However, users can still manually broadcast transactions if needed.

How does the 'Back-end + Signature' architecture work?

In the 'Back-end + Signature' architecture, users sign a message that describes the transaction they want to make. This signed message is sent to the backend, which creates a transaction and sends it to the smart contract, ensuring the signature is valid before processing.

What are the advantages and risks of the 'Back-end + Signature' architecture?

The advantage of this architecture is that it allows users to sign messages without paying transaction fees, with the backend covering those costs. The risk is that if the backend is compromised, the dApp could be affected, but the user’s signature remains secure.

What is the 'Back-end + Centralized Wallet' architecture, and why is it considered the least decentralized?

In the 'Back-end + Centralized Wallet' architecture, there is no wallet on the front-end. Instead, users interact with the backend using traditional payment methods, and the backend generates transactions on their behalf. This architecture is considered the least decentralized because the backend controls all the interactions with the smart contract, and if the backend is compromised, users lose access to the dApp.

What are the main benefits of the 'Back-end + Centralized Wallet' architecture?

The main benefit of this architecture is that it simplifies user onboarding, as users do not need to install a wallet or manage cryptocurrency. They can interact with the dApp using traditional payment methods like PayPal or credit cards.

How does the centralization in the 'Back-end + Centralized Wallet' architecture affect the security and control of the dApp?

The centralization in the 'Back-end + Centralized Wallet' architecture introduces significant risks. The backend controls all transactions and private keys, meaning if the backend is compromised or shut down, users may lose access to their funds and actions on the dApp. This setup offers minimal decentralization and user control.

Which Ethereum dApp architecture provides the most decentralization?

The 'Pure dApp Architecture' provides the most decentralization because both the smart contract and the front-end are decentralized, with the front-end being served from a decentralized file system like IPFS.

What is the main trade-off in choosing the 'Back-end + Signature' architecture?

The main trade-off in the 'Back-end + Signature' architecture is between decentralization and user convenience. While the backend handles transaction costs and ensures transaction validity, it adds a layer of centralization. The system is still secure due to user signatures, but the backend’s compromise could affect the dApp.