Method and security system for securing a flowable good

The invention relates to a security system for flowable products in storage and/or transportation tanks, which have openings at least for filling, removing and/or controlling purposes. The security system comprises a control device and write-read devices for data exchange with connection elements connectable to the openings. The connection elements have a code mark or a tag. With each opening is clearly associated a tag. With each opening is also associated a closure element as a connection element, on which is located the tag associated with the opening. The associations of tag and opening are controllable and storable in the control device and in the case of a specific association of all the tags with the particular openings a manipulation-free state can be displayed by the control device.