Processing a payment, by a secure computing system, from a payer to a payee operating a merchant computing system

A secure server that processes a payment transaction from a payer to a payee, the secure server comprising:

• one or more processors;
• and
• memory storing instructions that, when executed by the one or more processors, cause the secure server to:
• provide an application programming interface (API) to a merchant server providing a webpage to a payer computing system used by the payer, the API configured to:
• provide financial account registration and token retrieval functions that can be executed to process the payment transaction;
• provide access to the financial account registration and token retrieval functions to the merchant server;
• receive, from the merchant server via the API, at least one data element associated with the payer and a payment amount from the payer to the payee;
• authenticate the payee;
• execute the financial account registration function, upon initiation by the merchant server, by:
• generating a uniform resource locator (URL) to establish an encrypted connection via the internet between the secure server and the payer computing system, the URL comprising either:
• a dynamic URL generated by the secure server for the payer and the payee;
• or
• a static URL and a hypertext transport protocol (HTTP) parameter used by the secure server to identify the payer and the payee;
• establishing the encrypted connection, in response to an HTTP request for the generated URL, between the secure server and the payer computing system;
• outputting instructions to the payer computing system, in response to the HTTP request for the generated URL, to render a financial account registration request form that provides functionality for the payer to provide sensitive financial account information associated with a financial account;
• and
• outputting instructions to the payer computing system, in response to the HTTP request for the generated URL, to encrypt the sensitive financial account information provided by the payer and transmit the encrypted financial account information to the secure server, via the encrypted connection;
• receive the sensitive financial account information provided by the payer via the encrypted connection;
• store the sensitive financial account information in a secure storage location and perform each software process required to maintain compliance with one or more information security standards;
• execute a token retrieval function, upon initiation by the merchant server via the API, by:
• providing a non-sensitive electronic data token representing the sensitive financial account information to the merchant server;
• and
• processing the payment transaction using the sensitive financial account information, without providing the sensitive financial account information to the merchant server and without providing the non-sensitive electronic data token to the payer, by generating and transmitting an electronic request requesting that at least a portion of the payment amount from the financial account be forwarded to the payee.