A method of computing an exponent of a message m in an RSA cryptosystem having a private key d, a public key e and system parameters p, q where p and q are primes and ed=1 mod. The safety system includes a variable depth inflatable air bag cushion having at least one vent opening. Upon receiving an instruction of reporting a simulation result, snapshot simulation result reporting means 22 reports a physical disk capacity of the snapshot calculated by the snapshot simulation function. The media player may be distributed in multiple environments, and updates to the playlist may be automatically distributed to all instances where the playlist is referenced due to the centralized reference in the media player.