Customers pay for merchandise (Goods) by writing an electronic check that is transmitted electronically by email, fax or phone. The "cheque" is a message that contains all of the information that is found on an ordinary cheque, but it is signed digitally, or indorsed.
The digital signature is encoded by encrypting with the customer’s secret key. Upon receipt, the merchant or "payee" may further indorse by encoding with a private key. When the cheque is processed, the resulting message is encoded with the bank’s secret key, thus providing proof of payment. Various companies are selling Electronic Check software and services