According to the present invention, a computer system with a mechanism
for controlling the access rights for data to be used in common by multiple users,
which includes: data storage for the storing data in common; an access management
table including access management data for controlling access rights for the data
in common; and control mechanism for updating the access management data in response
to communication from a user who is authorized to grant access rights. Included
in the data in the access management table is information for data to be accessed,
identification information for a user who has been granted access rights, access
level information and identification information for the user who grants the access rights.
