• Payment by instruction. This is a credit/debit/ach transaction where the payer orders their bank or financial institution to take funds from their bank account and transfer it into a payee’s account.
  • Prepaid electronic cash. Essentially this is the electronic form of cash where a card or account is debited immediately and can be reloaded with electronic cash.
  • On-line. This is a payment protocol between the payer and payee that also involves a third party, such as a bank or credit card.
  • Off-line. This payment protocol does not involve a third party.
  • Secret key. Payment protocols must be verified. With cryptography, the transaction is authenticated. A secret key is where the payer and payee have shared a key that is only between them.
  • Public key authentication. Unlike secret keys, this form of authentication is available to the public.
  • Software-only. This is a low-cost system that can be placed on any computer in order to exchange funds electronically for ecommerce sites.