Design a Blockchain-Based System

Functional Requirements

1. Decentralization:

   • The system should operate on a decentralized network, ensuring no single point of control.

2. Data Integrity:

   • Ensure that once data is recorded in the blockchain, it cannot be altered retroactively.

3. Consensus Mechanism:

   • Implement a consensus algorithm (e.g., Proof of Work, Proof of Stake) to validate transactions and add new blocks.

4. Transaction Processing:

   • Allow users to initiate, validate, and confirm transactions.

5. Smart Contracts:

   • Support the creation and execution of smart contracts for automated and self-executing agreements.

6. Node Communication:

   • Enable nodes to communicate and synchronize with each other to maintain a consistent state across the network.

7. Security:

   • Implement cryptographic techniques to secure transactions and user data.

8. Scalability:

   • Design the system to handle an increasing number of transactions and nodes efficiently.

9. User Authentication:

   • Provide mechanisms for user identity verification and access control.

10. Data Storage:

    • Efficiently store blockchain data, including transaction history and smart contract states.

Non-Functional Requirements

1. Performance:

   • Ensure low latency in transaction processing and block validation.

2. Reliability:

   • The system should be resilient to node failures and network partitions.

3. Scalability:

   • Support a growing number of users and transactions without significant performance degradation.

4. Security:

   • Protect against common blockchain attacks such as 51% attacks, double-spending, and Sybil attacks.

5. Interoperability:

   • Allow integration with other blockchain networks and legacy systems.

6. Availability:

   • Ensure high availability and uptime, even in the presence of network disruptions.

7. Data Consistency:

   • Maintain data consistency across all nodes in the network.

8. Extensibility:

   • Design the system to accommodate future enhancements and new features.

9. Energy Efficiency:

   • Optimize the system to minimize energy consumption, especially if using energy-intensive consensus mechanisms.

10. Privacy:

    • Implement privacy-preserving techniques to protect user data and transaction details.