A browser extension system, comprising: a communication device configured to communicate with (i) a computing device executing a browser extension application and a web browser application (108; 600); and (ii) a networked system; a memory for storing instructions; and a processor configured to execute the instructions to perform operations comprising: maintaining data associated with the computing device; detecting, through the browser extension application, a field in a web page associated with the networked system and provided by the computing device through the web browser application; and in response to detecting the field: (i) automatically populating the field, through the browser extension application, with a secure token mapped to the data; (ii) detecting, through the browser extension application, a submission script associated with the web page; and (iii) automatically executing the submission script to submit the secure token through the browser extension application to the networked system, the automatically executing characterized by: modifying the submission script based on the automatically populated field, and automatically executing the modified submission script. a communication device configured to communicate with (i) a computing device executing a browser extension application and a web browser application (108; 600); and (ii) a networked system; (i) a computing device executing a browser extension application and a web browser application (108; 600); and (ii) a networked system; a memory for storing instructions; and a processor configured to execute the instructions to perform operations comprising: maintaining data associated with the computing device; detecting, through the browser extension application, a field in a web page associated with the networked system and provided by the computing device through the web browser application; and in response to detecting the field: (i) automatically populating the field, through the browser extension application, with a secure token mapped to the data; (ii) detecting, through the browser extension application, a submission script associated with the web page; and (iii) automatically executing the submission script to submit the secure token through the browser extension application to the networked system, the automatically executing characterized by: modifying the submission script based on the automatically populated field, and automatically executing the modified submission script. maintaining data associated with the computing device; detecting, through the browser extension application, a field in a web page associated with the networked system and provided by the computing device through the web browser application; and in response to detecting the field: (i) automatically populating the field, through the browser extension application, with a secure token mapped to the data; (ii) detecting, through the browser extension application, a submission script associated with the web page; and (iii) automatically executing the submission script to submit the secure token through the browser extension application to the networked system, the automatically executing characterized by: modifying the submission script based on the automatically populated field, and automatically executing the modified submission script. (i) automatically populating the field, through the browser extension application, with a secure token mapped to the data; (ii) detecting, through the browser extension application, a submission script associated with the web page; and (iii) automatically executing the submission script to submit the secure token through the browser extension application to the networked system, the automatically executing characterized by: modifying the submission script based on the automatically populated field, and automatically executing the modified submission script. modifying the submission script based on the automatically populated field, and automatically executing the modified submission script.