Cloud-based electronic payment processing

A payment processing server comprising:

• a computer processing system comprising a pending transaction database and configured to:
• (i) generate an asymmetric cryptographic key pair, generate a unique single-use payment number, over one secure communications channel provide a mobile device with a credential comprising one cryptographic key of the cryptographic key pair, and save another cryptographic key of the cryptographic key pair in the pending transaction database in association with the single-use payment number and a financial account, the cryptographic key pair and the single-use payment number each being uniquely associated with the financial account;
• (ii) encrypt the single-use payment number with the another cryptographic key, and provide the mobile device with the encrypted single-use payment number over another secure communications channel distinct from the one secure communications channel, the encrypted single-use payment number not identifying the financial account;
• (iii) receive from a payment terminal a payment completion request requesting completion of a financial transaction, the payment completion request including the encrypted single-use payment number decrypted with the one cryptographic key;
• and
• (iv) query the pending transaction database with the decrypted single-use payment number to identify the associated financial account, and effect completion of the financial transaction using the identified financial account.

A method of cloud-based electronic payment processing, the method comprising:

• a mobile device receiving from a payment processing server over one secure communications channel a credential comprising one cryptographic key of an asymmetric cryptographic key pair, the payment processing server being configured to save another cryptographic key of the asymmetric cryptographic key pair in a pending transaction database in association with a unique single-use payment number and a financial account, the cryptographic key pair and the single-use payment number each being uniquely associated with the financial account;
• the mobile device receiving from the payment processing server over another secure communications channel distinct from the one secure communications channel the single-use payment number encrypted with the another cryptographic key, the encrypted single-use payment number not identifying the financial account;
• the mobile device decrypting the encrypted single-use payment number with the one cryptographic key;
• and
• the mobile device initiating completion of a financial transaction by providing a payment terminal with the decrypted single-use payment number, the payment terminal being configured to provide the payment processing server with a payment completion request requesting completion of the financial transaction, the payment completion request including the decrypted single-use payment number, the payment processing server being configured to query the pending transaction database with the decrypted single-use payment number to identify the associated financial account and to effect completion of the financial transaction using the identified financial account.