Systems and methods for associating sessions of encrypted identifiers are provided. A collection of data packets received during one or more sessions within a time period may be retrieved. Each packet in the collection may be associated with a unique identifier of a respective session. An epoch time may be calculated for each of the retrieved data packets based on the determined skew and respective timestamp information of the data packet. It may be identified as to whether each of the calculated epoch times matches a previously calculated epoch time for a packet associated with a previous session or a session that has previously been associated with a selected session. The timestamp information may be associated with a browser identifier and subject to encryption/decryption by an identifier server or authorized parties.