Patent ID: 8332952

Claim:
Apparatus comprising at least one physical computer-readable storage medium having stored thereon computer-executable instructions that, when loaded into at least one hardware processor and executed, transform the hardware processor to perform as a server that provides a process comprising: receiving from a client browser consecutive requests to generate respective canary values in connection with providing respective contents maintained on at least one server system; computing, by at least one hardware processor, the canary values, in response to the requests, wherein each canary value is computed based on identity information associated with a user, based on a site-specific value associated with a website accessed by the user, and based on a time value associated with one of the requests, wherein the canary values each have respective sequential time values that correspond to a series of consecutive time windows; receiving, by at least one hardware processor, post requests to post data from the client browser; determining, by at least one hardware processor, whether to post the data of the post requests by, for a given post request with a given one of the canary values, first determining that the given canary value is not valid for the current time window, and in response determining that the given canary value is valid for a time window immediately preceding the current time window; and posting, according to the determining, the data of the post requests.