Patent ID: 8151107

Claim:
A system for detecting concurrent logins, the system comprising: a message receiving unit configured to receive a log message which is indicative of a user identifier of a user, login/logout state of the user, and a session identifier, from an external server; a corresponding message retrieval unit configured to retrieve a corresponding message of the received log message from a memory, wherein the corresponding message is a log message containing the same user identifier and the same session identifier as contained in said received log message, and comprises a login/logout state of the user that is opposite to the login/logout state of the user in the received log message; a message processor configured to remove said received log message and said retrieved corresponding message from the memory if the corresponding message is retrieved from the memory, and to store said received log message in the memory if said corresponding message is not retrieved from the memory, wherein if the corresponding message is not retrieved from the memory, and if another log message is stored in the memory, the message processor registers the received log message and the another log message to a force logout candidate list, the received log message and the another log message both having the login state and the same user identifier.