Algorand Network Overview

Algorand is a highly efficient, secure, and scalable blockchain platform that aims to provide a decentralized infrastructure. At its core, Algorand utilizes a permissionless, pure proof-of-stake consensus mechanism to ensure network consensus and security. The network consists of two primary types of nodes, each playing a crucial role in maintaining the integrity and functionality of the blockchain:

1. Participation Nodes: Participation nodes are responsible for validating and propagating transactions and participating in consensus. They actively contribute to the consensus protocol, play essential roles in block proposal and validation, and maintain the integrity of the network.

2. Relay Nodes: Relay nodes serve as intermediaries between participation nodes, propagating information across the network. They broadcast newly created blocks, transactions, and consensus messages to other nodes. Relay nodes are crucial for ensuring the timely dissemination of information and maintaining the overall connectivity of the network.

Participation nodes in the Algorand network can be configured as either “archival nodes” or “lightweight nodes”. Archival nodes maintain a full copy of the blockchain, making them ideal for supporting blockchain indexers. These indexers collect comprehensive data about blocks and transactions, enabling various analyses of the blockchain's state information. In contrast, lightweight nodes store only the most recent blocks necessary for active participation in the protocol. While lightweight nodes consume fewer computational and storage resources compared to archival nodes, they lack the ability to readily support tools requiring historical blockchain data, such as indexers.

Nodes in Algorand's network are connected through a peer-to-peer (P2P) overlay network. Algorand employs a "secure gossip" mechanism that ensures the integrity and authenticity of the shared information. It utilizes cryptographic signatures and verifiable random functions (VRFs) to guarantee that only valid and authorized information is propagated through the network.

A participation node establishes direct connections with a subset of relay nodes, typically the ones in close proximity geographically. However, participation nodes do not directly connect with other participation nodes. In contrast, relay nodes maintain connections with both participation nodes and other relay nodes within the network. This architecture ensures that communication latency is minimized, facilitating rapid message propagation across the network. The following diagram illustrates this architecture:

By strategically connecting participation nodes with nearby relay nodes and allowing relay nodes to interconnect, the Algorand network optimizes efficiency and responsiveness in message dissemination.

More information about node types and the Algorand network can be found in Algorand’s Developer Portal.