Security seals are safety products that visually identify if a seal, container, package or enclosure has been opened. Tamper-evident security seals are widely used in industry, government, and the consumer world to detect unauthorized attempts to open a secured item. Whether a piece of foil on a jar of peanut butter or a fiber-optic loop on a radioactive waste container, security seals are intended to leave unambiguous, non-erasable, visual evidence of unauthorized ingress.

Applications

Security seals are used for many different applications including access control, records integrity, inventory, shipping integrity, container seal security, theft prevention and detection, hazardous materials accountability, computer security, nuclear nonproliferation, national defense and homeland security seals, law enforcement, customs, counterterrorism, counterespionage, and consumer product protection.  Specific types of security seals include lead seals, numbered seals, railcar seals, and truck seals.

Types of Security Seals

Security seals can be roughly divided into three types: tamper-evident seals, barrier seals, and electronic seals. Tamper-evident seals that provide evidence of ingress or contamination; barrier seals, which serve to prevent ingress; and electronic security seals that actively monitor for tampering and can provide a real-time alert if tampering occurs.  Tamper-evident seals are simple seals such as frangible foils or films, plastic wraps, pressure-sensitive adhesive tapes, crimped cables or other (theoretically) irreversible mechanical assemblies. They are not designed to provide additional security, only to provide evidence of tampering, should it occur.  Barrier seals are devices or materials such as snap seals, cables, padlocks, container seals and bolt seals that passively serve to prevent invasion. When breeched, they do provide physical evidence of tampering (e.g., broken straps or chain links, or lack of a seal if completely removed). In addition to physical seals, security seals can include electronic systems (reminiscent of burglar alarms) that continuously monitor for changes, such as attempted ingress through an electrical cable or fiber-optic bundle.  They can provide output to monitors or security stations allowing guards or law enforcement to intervene. These devices are often referred to as e-seals.