LNPB: A Light Node for Public Blockchain with Constant-Size Storage

In the blockchain system, the light node uses a simplified transaction verification method. Its storage overhead increases linearly with the size of the blockchain, which can quickly become prohibitive for mobile and IoT low-end devices in the blockchain system. However, most existing schemes only achieve limited storage compression, apply only to UTXO scenarios, or cannot verify the transactions independently. This paper proposes a light node for public blockchain with constant-size storage called LNPB. LNBP fuses the blockchain verification and the simple payment verification protocols to achieve a more succinct and secure transaction verification protocol with constant-size storage. It applies to UTXO and non-UTXO scenarios. To this end, we re-design the block header, which contains a constant-size summary and an RSA modulus. Then we use an RSA encryption accumulator to calculate this summary. The light node only stores the summary of the latest block when verifying the transaction. In generating the proof of the transaction by full node, we employ the Merkle Mountain Range to store the intermediate results of the summary, which makes the proof generating faster. In addition, we conduct simulation experiments and analysis on LNPB, and compare it with existing schemes. The results indicate that LNPB achieves the expected goals, and can save the storage and computation overheads.