A method, system, and connector interface for authenticating an accessory. During its periodic update request, a network security module blocking the network activities of the network device requests updated security measures from an administrator-configurable security service. Market data sent to client devices might include price information. Memory is also included for storing such data for subsequent analysis to determine the individual leg performance of a cyclist during a race or training session. By determining an initial value of S and interleaving the value of M stored in the memory, the base sequence S can be calculated without modulo calculation.