The most repeated mantra in the cryptocurrency ecosystem is "don't trust, verify". But most users never verify anything: they delegate that responsibility to someone else's node, usually an exchange, wallet provider, or remote RPC service. That is not financial sovereignty; it is still trust in third parties, just with a better interface.

What a full node actually does

  • Downloads and verifies every block from the genesis block, checking that all transactions comply with consensus rules.
  • Validates that transactions do not spend coins that are unavailable or already spent (double-spend prevention).
  • Rejects blocks that violate protocol rules, regardless of how much hashrate is behind them.
  • Propagates transactions and blocks to other nodes in the network.
  • Serves as a local reference point for your wallet: your transactions are verified against your copy of the chain, not someone else's.

The problem with using someone else's node

When your wallet queries an external node to verify whether a transaction was confirmed, it is revealing which addresses you care about. This allows the node operator to build a profile of your financial activities: what you receive or send, when, and how often. If that node belongs to a chain-analysis company, that profile can be sold or shared with authorities.

Furthermore, an external node can lie to you. It can tell you a transaction was confirmed when it was not, or it can hide a chain reorganization from you. Your own full node cannot be deceived that way because it independently verifies protocol rules.

Nodes enforce the network rules

Miners produce blocks, but it is full nodes that decide whether to accept them. During the Bitcoin scaling conflict (2015–2017), it was demonstrated that miners cannot force a protocol change if the network's nodes reject it. Nodes enforce consensus: if users, businesses, and node operators do not accept the new rules, a hard fork will not be recognised by that network.

What resources do I need?

  • Bitcoin: ~750 GB storage (SSD strongly recommended; HDD is possible but very slow), 4 GB RAM minimum, stable internet connection. A Raspberry Pi 5 with external SSD can run Bitcoin Core, though initial sync will be slower than on more powerful hardware. A mini-PC with 8 GB RAM is recommended for optimal performance.
  • Monero: ~250 GB storage for a full node with the blockchain in default mode (pruned available with ~100 GB), 2 GB RAM. monerod is the official daemon.
  • Bitcoin Cash: ~250 GB. Bitcoin Cash Node (BCHN) is the most widely used client.
  • In all cases, the initial sync process (IBD, Initial Block Download) can take from hours to days depending on hardware speed and connection.

Running a node does not require mining. It generates no direct economic rewards. But it is the most concrete act of sovereign participation in a decentralised network. If nobody runs their own nodes, the network becomes a centralised service with the appearance of a blockchain.

If this topic matters to you, read our guides on custody, mining addresses, and payment verification as well. They will help you reduce dependencies before you start mining.