Simplified Payment Verification (SPV)
sovereign assets • layer 1s • payment networks
Simplified Payment Verification (SPV) is a method used by lightweight or mobile cryptocurrency wallets to verify that transactions have been confirmed on the blockchain without downloading the full ledger. Instead of storing all transaction data, SPV clients download only block headers and use Merkle proofs to confirm the inclusion of specific transactions.
Introduced in the original Bitcoin whitepaper, SPV allows for secure and efficient verification with minimal storage and bandwidth requirements. While SPV wallets are faster and more accessible, they rely on full nodes for complete data, making them slightly less trustless than running a full node.
SPV is commonly used in mobile and browser-based wallets that prioritize speed and simplicity while still offering secure blockchain interaction.
Use Case: A Bitcoin wallet app on a smartphone can use SPV to confirm incoming payments by downloading only block headers and checking Merkle proofs, saving storage space while still verifying transactions securely.
Key Concepts:
- Block Headers — Contain the Merkle Root and metadata needed for SPV validation.
- Merkle Root — The cryptographic summary that enables Merkle proofs for transactions.
- Light Node — Nodes that rely on block headers instead of storing the full blockchain.
- Full Node — Provides the complete blockchain data that SPV clients depend on for verification.
Summary: SPV offers a lightweight, efficient way to confirm blockchain transactions, balancing security with convenience, especially for mobile and resource-limited devices.