The IoT Packet Verifier reads published packet reports and verifies that the payer has a sufficient balance to pay for the packet. If it does, it burns the data credits on the Solana chain, tells the config server to enable the owner, and writes a valid packet report to S3. If the payer's balance is insufficient, the verifier will tell the config server to disable the owner and writes an invalid packet report to S3.

Checking the balance of an owner on the Solana chain is cheap, but burning data credits is quite expensive, and we are limited to burning the data credits of one payer every one second. Therefore, the verifier is split into three parts:

• An in-memory cache that contains the previously recorded balance of the payer. This cache allows us to quickly debit a payer and check their balance without having to burn their credits on chain each packet.
• A postgres database that contains the pending burn amounts for each payer. When a payer is debited, the amount is added to the database, ensuring that if the packet verifier crashes the state will be recoverable.
• A burner process that polls the database for a random payer that exceeds a certain amount of data credits for payment. This process issues a burn transaction to the Solana chain and will remove that burned amount from the in-memory cache.