A method includes authorizing a user to participate in a survey, generating a key associated with a user identifier and a survey identifier, sending the key to a user terminal, directing the user terminal to a survey uniform resource locator (URL), connecting communicatively with the user terminal via a second URL, determining whether the second URL designates the survey as completed, retrieving the encrypted key from the user terminal responsive to determining that the second URL designates the survey as completed, and updating the status of the survey in a memory responsive to verifying the integrity of the encrypted key.