Hitherto synchronization of a number of devices has involved a large number of comparison steps between actual data or changes in data. Such comparison has potentially involved extensive redundant comparison steps. Another problem with existing synchronization methods is that such synchronization has been effected based upon the systems clocks defined by the devices. Those system clocks can be modified either intentionally or malevolently with disastrous consequences for subsequent synchronization of the devices. Accordingly, the present invention relates to a method of synchronization between three or more devices, the method involves: storing an indication of the device or devices involved in each synchronization event; storing data changes received during a current synchronization event together with the device submitting those changes; and applying the data changes subsequent to the stored synchronization event for the or each device.