A computer-implemented method for securely receiving data via a third-party webpage , comprising: generating , with a payment web server , configuration data in response to a request from a merchant web server , the configuration data comprising a public key of a first key pair; digitally signing , with the payment web server , the configuration data based on a private key of a second key pair; transmitting , by the payment web server , the digitally signed configuration data to the merchant web server ; in response to the merchant web server receiving the configuration data from the payment web server , transmitting, by the merchant web server , data comprising the configuration data to a user device , wherein the data is configured to cause the user device to render a webpage through a web browser application executed by the user device , the webpage including a master frame and at least one other frame , wherein the frames (303a-303c) load content from a domain that is independent from a domain that hosts the webpage ; verifying , with the user device , the digitally signed configuration data based on a public key of the second key pair; rendering, by a browser executed by the user device , the webpage ; establishing communication between the master frame and the one other frame in response to rendering the master frame and/or verifying the digitally signed configuration data, wherein the digitally signed configuration data restricts communication of the master frame to the at least one other frame and the merchant webpage ; aggregating, by the master frame , data input by a user from each frame (303a-303c); encrypting, by the master frame , the data input by the user using the public key of the first key pair to generate encrypted data; and receiving , from the master frame at the payment web server , the encrypted data. generating , with a payment web server , configuration data in response to a request from a merchant web server , the configuration data comprising a public key of a first key pair; digitally signing , with the payment web server , the configuration data based on a private key of a second key pair; transmitting , by the payment web server , the digitally signed configuration data to the merchant web server ; in response to the merchant web server receiving the configuration data from the payment web server , transmitting, by the merchant web server , data comprising the configuration data to a user device , wherein the data is configured to cause the user device to render a webpage through a web browser application executed by the user device , the webpage including a master frame and at least one other frame , wherein the frames (303a-303c) load content from a domain that is independent from a domain that hosts the webpage ; verifying , with the user device , the digitally signed configuration data based on a public key of the second key pair; rendering, by a browser executed by the user device , the webpage ; establishing communication between the master frame and the one other frame in response to rendering the master frame and/or verifying the digitally signed configuration data, wherein the digitally signed configuration data restricts communication of the master frame to the at least one other frame and the merchant webpage ; aggregating, by the master frame , data input by a user from each frame (303a-303c); encrypting, by the master frame , the data input by the user using the public key of the first key pair to generate encrypted data; and receiving , from the master frame at the payment web server , the encrypted data. <EOS>