
Security seals are tamper-evident mechanisms that seal valuable material in a room, cabinet, vehicle, or other storage facility. One common use is to seal cargo in transit
shipping container
A shipping container is a container with strength suitable to withstand shipment, storage, and handling. Shipping containers range from large reusable steel boxes used for intermodal shipments to the ubiquitous corrugated box design, corrugated b ...
s in a way that provides
tamper evidence and some level of rudimentary security. Such seals can help to detect
theft
Theft (, cognate to ) is the act of taking another person's property or services without that person's permission or consent with the intent to deprive the rightful owner of it. The word ''theft'' is also used as a synonym or informal shor ...
or contamination, either accidental or deliberate. Security seals are commonly used to secure truck trailers, vessel containers, chemical drums, airline
duty-free
A duty-free shop or store is a retail outlet whose goods are exempt from the payment of certain local or national taxes and duties, on the requirement that the goods will be sold to travelers who will take them out of the country, who will ...
trolleys,
keys and
utility meters. Typically they are considered an inexpensive way of providing tamper evidence of intrusion into sensitive spaces.
Vulnerabilities
Security seals are not designed to resolve all security problems:
The same organization demonstrated that a trained individual was able, using low-tech methods, to defeat 90% of the 244 seals they studied in less than 3 minutes, and all of them in less than 44 minutes. They offer ideas on countermeasures, and are exploring the promising option of "anti-evidence" seals.
Operation
Security seals can be split into two main groups:
single-use
A disposable (also called disposable product) is a product designed for a single use after which it is recycled or is disposed as solid waste. The term is also sometimes used for products that may last several months (e.g. disposable air filter ...
and reusable. Single-use seals are typically made of plastic or metal, and the used material and production technology is the key to their security level. Reusable seals are usually electronic or mechanical rather than just made from plastic, and if purely plastic, only one part is reusable. Electronic and mechanical seals are generally used for the
transportation industry, with seal fixed to the back of
truck
A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...
s,
trailers, and
shipping container
A shipping container is a container with strength suitable to withstand shipment, storage, and handling. Shipping containers range from large reusable steel boxes used for intermodal shipments to the ubiquitous corrugated box design, corrugated b ...
s. A reusable mechanical or electronic seal can be fitted to the rear or loading
door
A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a ''doorway'' or ''portal''. A door's essential and primary purpose is to provide securit ...
s, extending a cable from itself through fixing points on the doors, and when sealed generating a unique number which is logged. When the door is next opened this number changes, so it provides tamper evidence for the load.
High Security Seals
A High Security Seal is constructed and manufactured of material such as metal or metal cable with the intent to delay intrusion and have been designed to conform with world customs and ISO security seal standards.
The International Standards Organization (ISO) published the new version o
ISO 17712on 15 May 2013. The major changes in the new edition concern Clause 6, Evidence of Tampering. Changes were required due to the demonstrated impracticality of tamper-related tests in ISO 17712:2010 edition.
A measure of a seal's security is whether it has obtained an ISO 17712:2013 rating. US
Customs-Trade Partnership Against Terrorism (C-TPAT) and the World Customs Organization's Framework of standards, endorsed and encouraged the use of
ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
compliant seals.
The requirements for certain security level of seals are defined in the ISO 17712. The seals that belong to the High security level and Security level are also called "barrier seals". They are made of different metals or metal alloys, meaning that they require special tools to be opened, such as bolt cutters or pliers. Cable seals and bolt seals also fall into this category. Designed to deter opportunistic theft of high value goods, they also can often be branded and numbered to improve
tamper resistance
Tamperproofing is a methodology used to hinder, deter or detect unauthorised access to a device or circumvention of a security system. Since any device or system can be foiled by a person with sufficient knowledge, equipment, and time, the term " ...
and provide excellent security for containers. The seals that are in the Indicative level as to ISO 17712 are made of plastic or thin metal.
Security Seal Manufacturers have worked alongside ISO Security Auditors to provide the following information to help inform businesses and other interested parties about the new edition.
(HMRC) Customs Accepted Seals
Customs accepted seals are security seals which the customs department of a given country will accept as a secure seal to be placed onto a container. This does not mean that all exporters or importers should place a customs accepted seal on their containers or trailers. Many businesses who transport high value goods like to use Customs Accepted Seals as these seals have been through rigorous testing and are of high quality.
The UK Security Seal Testing Authority tests these seals on various points such as "Tensile Strength", "Effects of Heat", "Direct Effects of Freezing", "Effective Numbering & Marking", "Tamper Evidence", and more.
UK Customs Accepted seals are sorted into three various categories, Group 1 consists of seals which withstand a force of 1000 kg, Group 2 consists of seals which withstand a force of 250 kg and Group 3 consists of other accepted seals. View all UK customs accepted seal
here
Metal seals

There are several basic designs of the metal seals; bolt seals, ball seals, and cable seals.
Bolt seals are used to secure shipping containers, trucks, and trailers. A bolt seal used for securing containers must conform to the ISO 17712 high security seal in order to be accepted by customs all around the world in ocean shipping. The C-TPAT
(Customs Trade Partnership Against Terrorism) specifies ISO 17712 compliant security seals to be used. Bolt seals are generally closed by hand (by pushing the seal body and head together) and opened with the use of bolt cutters. This gives a strong and secure seal for transportation, while remaining convenient for staff in ports and warehouses.
Cable seals
Cable seals allow for more versatile application, as they have variable length of the locking mechanism limited only by the cable length. Typical applications include sealing trucks and railway cars transporting valuable commodities. An internal locking mechanism prevents the cable from being retracted. Most cable seals are classified as security or high security level as to ISO 17712.
All ISO 17712 compliant seals are numbered on both seal body and head, to prevent substitution of either part. This is usually done using laser marking, which cannot be rubbed off.
Ball seals are commonly used for securing trucks. They consist of a metal strip with a punched hole, attached to a housing section. When the strip is bent and threaded through the hole, a ball inside the housing section locks it in place. Most ball type seals belong only to the indicative level as to ISO 17712.
Plastic seals

Plastic security seals are manufactured normally in two styles; adjustable or fixed-length. Adjustable-length seals can fit many applications from securing the neck of a bag or mail sack to sealing chemical drums, first aid kits, and fire extinguishers. They have an adjustable length much like a cable seal but offer a much higher security level and an audit trail due to sequential numbering and the ability on some seals to be bar-coded and have a company name and logo printed or laser etched on.
Fixed-length seals tend to be more tamper resistant than variable-length as there are no sliding parts, they simply "click" into place to lock, which can make them easier to fit than variable-length seals. Most fixed-length seals can also be branded and numbered for extra security. Fixed-length is often the choice of single-use security seals for transport applications.
Padlock seals are usually supplied as a completely plastic seal, shaped as a standard
padlock
Padlocks are portable Lock (security device), locks with a shackle that may be passed through an opening (such as a chain, chain link, or hasp staple) to prevent wikt:use, use, theft, vandalism or harm.
Naming and etymology
The term '':wikt: ...
would be. Technically, they can be classed as a fixed-length seal. They feature the same types of
tamper-evident
Tamper-evident describes a device or process that makes unauthorized access to the protected object easily detected. Seals, markings, or other techniques may be tamper indicating.
Tampering
Tampering involves the deliberate altering or adulterat ...
protection as variable-length and fixed-length have available - numbering, bar-coding, and branding - but fit some different applications. The most common use for these seals is for airline duty-free trolleys. One reason for this is that plastic padlocks can be placed over a locking part as any metal
padlock
Padlocks are portable Lock (security device), locks with a shackle that may be passed through an opening (such as a chain, chain link, or hasp staple) to prevent wikt:use, use, theft, vandalism or harm.
Naming and etymology
The term '':wikt: ...
would be to secure, but do not require keys to open, they simply break off at their built in break point using hands or a small pair of wire cutters. They are secure due to the audit trail available as a result of the sequential numbering.
Meter seals are used with electric or gas or water meters and usually molded in polycarbonate. The transparent body of the seal means that the locking mechanism is visible, and can provide clear indication of tampering. Meter seals can withstand exposure to sunlight and extreme weather, and a wide range of temperatures. Designed for only a single use, they are destroyed when removed. Some meter seals contain components which glow under
ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...
light, allowing the seal to be easily located in darkness.
Special
security tape
Security tape (or security label) is a type of adhesive tape used to help reduce shipping losses due to pilfering and theft. It helps reduce tampering or product adulteration. It is often a pressure-sensitive tape or label with special tam ...
s and
label
A label (as distinct from signage) is a piece of paper, plastic film, cloth, metal, or other material affixed to a container or product. Labels are most often affixed to packaging and containers using an adhesive, or sewing when affix ...
s have high bond-strength adhesives in combination with backing that are designed to fracture or delaminate under designated conditions to indicate premature attempts at opening. Custom printing, holograms, and
security printing
Security printing is the field of the printing industry that deals with the printing of items such as banknotes, cheques, passports, tamper-evident labels, security tapes, product authentication, stock certificates, postage stamps, and identity c ...
often assist in deterring and indicating tampering.
Technologies for marking the seals
The seals can be individualized to fit the needs of the user. Typical marking includes logos, special texts, white pads for writing by hand, consecutive numbering, and 1D and 2D
bar code
A barcode or bar code is a method of representing data in a visual, Machine-readable data, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly ref ...
s. Several marking technologies are in use, including
hot stamping
Hot stamping or foil stamping is a printing method of relief printing in which pre-dried ink or foils are transferred to a surface at high temperatures. The method has diversified since its rise to prominence in the 19th century to include a var ...
,
inkjet printing
Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper or plastic substrates. Inkjet printers were the most commonly used type of printer in 2008, and range from small inexpensi ...
,
laser engraving
Laser engraving is the practice of using lasers to engrave an object. The engraving process renders a design by physically cutting into the object to remove material. The technique does not involve the use of inks or tool bits that contact th ...
, and
thermal printing
Thermal printing (or direct thermal printing) is a digital printing process which produces a printed image by passing paper with a Thermochromism, thermochromic coating, commonly known as thermal paper, over a print head consisting of tiny el ...
.
C-TPAT
The
Customs-Trade Partnership Against Terrorism (C-TPAT) is a voluntary
supply chain security
__NOTOC__
Supply chain security (also "supply-chain security") activities aim to enhance the security of the supply chain or value chain, the transport and logistics systems for the world's cargo and to "facilitate legitimate trade".Government ...
program led by U.S. Customs and Border Protection (CBP) and focused on improving the security of private companies' supply chains with respect to terrorism. The program was launched in November 2001 with seven initial participants, all large U.S. companies. Large-scale Security Seal producers were included within the "invited foreign manufacturers" segment of the ordinance. C-TPAT-compliant security ties indicate they are compliant with international shipping security standards.
See also
*
Package pilferage
*
Security bag
*
Tamper-evident technology
Tamper-evident describes a device or process that makes unauthorized access to the protected object easily detected. Seals, markings, or other techniques may be tamper indicating.
Tampering
Tampering involves the deliberate altering or adulterat ...
References
*ISO 17712:2013 Freight containers — Mechanical seals
{{Authority control
Packaging
Security