Off-chain vouchers let a payment system acknowledge many purchases quickly while deferring expensive final settlement. Each voucher can identify the parties, amount, resource, sequence or nonce, expiration, and evidence needed for later reconciliation.
The voucher system must prevent forgery, duplication, overspending, and replay. Escrow or bounded credit backs the obligations, and batch settlement later converts the verified voucher total into final on-chain transfers.
ELI5
An off-chain voucher is a verifiable digital IOU for a payment that will be settled later. It records one purchase without immediately placing a separate transaction on the blockchain.
For example, an agent may receive one signed voucher for each tiny data request. At the end of a period, the service totals the valid vouchers and settles them together from funds held in escrow.
