Security seals are tamper evident mechanisms used to seal cargo in transit shipping containers in a way that provides tamper evidence and some level of security. Such seals can help to detect theft or contamination, either accidental or deliberate. Security seals are commonly used to secure truck trailers, vessel containers, chemical drums, airline duty-free trolleys, and utility meters. Typically they are considered an inexpensive way of providing tamper evidence of intrusion into sensitive spaces.