Abstract: A panel having a central panel element formed of a composite material, having peripheral edges formed of a weldable material, such as steel. In one form, the panel element is rectangular, and the panel element on two of its opposite edges have a corrugated profile, while the other two of its opposite edges have a linear profile. Multiple panels may be joined together by welding at the peripheral edges, to form a secure container. The composite material of the panel element in some forms, includes intrusion sensors, for example including optical fiber pathways at electrically conductive pathways, as well as processors for effecting data transfer and analyses and secure communications. In some embodiments, the electrically conductive pathways include one or more bypass resistors to produce a different circuit resistance upon interruption of one or more of the pathways.