Origins of security seals
Security seals have existed in some form or another since ancient times as people have been concerned with protecting their valuables against thieves and other nefarious individuals.
Seven-thousand-year-old intricate stone carvings have been found that were pressed into clay to seal jars containing documents or valuables. Kings sealed their letters and sensitive documents with wax and the insignia borne exclusively on their personal ring as a means of evidencing tampering or premature opening of the sealed document. The signet also proved who the letter was from, or in modern terms, provided brand authentication.
Today Security Seals can offer some of the same practical uses, although technology has advanced far beyond wax seals and the relatively simple means of bypassing them. Today’s security seals still provide brand protection, confirming a product’s originality and integrity, but they also offer higher security and make it more difficult for trained individuals to break or bypass the seals and tamper with or steal sealed goods.
The evolution of security seals and their application
Originally, there were only a few seal types (mainly made of lead, or tinplate steel), with some variations. Through the last century, uses and number of security seal types proliferated into thousands. Growth in trucking and over-the-road delivery spawned many more seals and seal uses. Then international ocean containers created an entire industry of heavy bolt and cable devices to secure the doors. Plastics, heavy metal, cable, and wires are now used to make mechanical seals ranging from small and simple lightweight plastic security seals to large iron and steel devices that serve as barriers to unauthorized opening.
More recent developments include advanced electronic devices with RFID data recording and monitoring functions, remote reading, GPS tracking and more. There are also new adhesive labels and tapes, holographic images, thermal activated inks, and high-tech printed adhesives that leave an impression and/or destroy a printed pattern if the security tape is removed.
Security seals are a tool to deter and detect unauthorized opening of a closure. They differ from locks in that they are intended to be used only once, and then destroyed. Early seals were intentionally made to be easily cut open after use. By around 1980 the added dimension of a high strength barrier seal became popular in transportation. Now, some security seals function both as a strong disposable lock and a seal — to provide evidence of entry or violation.
When security seals are found tampered with or violated, it is the tampering indicators which allow the user to begin investigating, ultimately catching and stopping the violator. The seal does not stop entry. But a higher strength security seal can slow a thief, and reduces the likelihood of vandalism or theft of “convenience” by someone with no concern for leaving evidence.
Seal violation takes various forms: opening and closing and hiding the breakpoint to fool the observer, substitution of parts, modification of marking, or substitution of whole (clone) seals. The initial discovery of tampering may take place when the seal is cut and taken out of use. It may also be found on examination of the seal after it is opened by the user and checked at another location. If not examined by an informed person, tampering with or violation of the security seal may not be discovered at all.
Once discovered, the process is normally one of systematically narrowing the time and/or place the violation occurs. This tells an investigator who could potentially be violating (or attempting to violate) a secured container or device.
Stronger security seals require stronger tools and more time to remove. However, for investigative and enforcement purposes they serve the same function as lighter seals. With systematic inspection and observation, all tamper evident seals can help catch or deter thieves.
Modern seal classifications and regulation
There are two general seal types, but 3 categories in today’s official government terms. The two main types are:
Indicative security seals serve the function of providing tamper evidence but are easily broken or cut open with light tools. (Sometimes called tamper-evident seals.)
Barrier seals are higher strength security seals that can provide tamper-evidence and serve as a one-time lock to slow down and deter theft or vandalism. They require large tools to cut open.
Many still refer to all seals as Security Seals. It is a simple and accepted generic classification. It helps in common language to distinguish this type from seals used for other purposes not related to security and tampering. (ie o-ring seals and the like)
New ISO17712 standards for seals use three specific classifications, according to strength. You can find more information about ISO17712 by reading our international regulation and standards article on high security container seals.
“INDICATIVE” SEALS
All light duty seals that can be removed by hand or with basic tools such as shears or common household cutters. Indicative seals are the most used and found in the most applications. These include almost any closure, like totes, bags, wheel carts, ballot boxes etc. Also on stationary closures such as utility meters, valves, cabinets, lockers, bins, and cages.
“SECURITY” SEALS
These are of intermediate strength and require a stronger or larger tool and more effort to cut open than indicative seals. Added strength can help avoid accidental breaking or easy entry, without tools.
“HIGH SECURITY” SEALS
This term is now applied to barrier seals that are the strongest and most difficult to cut open. Larger and stronger tools are needed to cut them open. The standard testing for this category requires resistance to specific levels of pull, bending and crushing. Refer to the standards of ISO17712 and C-TPAT for more on this.
Seals tested and certified to meet the High Security standards of ISO-17712 are stamped with the letter (H) and the identity of the manufacturer. Ocean containers, rail cars, and long-haul trucks are the most common commercial uses for barrier security seals.
While useful in general, these 3 classifications are limited to lab tests for strength and can exclude good seals from being considered for many applications. Worse, the terms may confuse the buyer about the real level of security they can get for their specific application. Much depends on the specific design, how it fits the application and especially on how, and how well, the security seals are applied, controlled and examined. A very strong or well-made seal has little security value if it does not fit or is not carefully documented and inspected throughout its use by reliable people.
Effectiveness of security seals and countermeasures
Seals alone cannot protect cargo containers and other closures from access by motivated people who intend harm. Nor can any technology. It is unrealistic to expect absolutes.
However, each step toward improving design and application of tamper evident seals and related technologies improves the odds of detecting and preventing loss and reduces points of opportunity. This is what security measures are intended to accomplish.
We have over 100 years of global experience in the seal industry. We supply security seals and other devices to almost every segment and enterprise of industry, government, and the military. While each situation is unique, there is one overarching and often misunderstood reality of the effectiveness of security seals.
All Security Seals can be defeated.
All Security Seals can be effective.
Both statements are true, and the paradox is explained this way:
- Seals can be defeated or bypassed without leaving obvious evidence–given sufficient opportunity, time, and tools. So can safes, door locks, padlocks, alarms etc.
Security seals can be made to work effectively in tamper detection, with appropriate application, a strong and well-enforced program for control and inspection, plus use of well-considered and adaptable countermeasures.
For a security seal to be effective, there must be a reasonable level of reliability upon the points of locking and opening.
Who is handling the seals (and how) is what matters most. Seals are used to great benefit in countless applications every day. One can argue which ones work best (or don’t work) for a given use, or even if they are necessary for your purposes. But, if you use security seals, it is more important to deal with how they will be handled. This is primary and helps determine the type of seal that fits your purpose.
For a seal to be effective there needs to be a real effort on the user’s part. Using tamper evident seals effectively is a far greater challenge than finding a design that fits.
Uncovering tampering of a seal requires a reasonable level of reliability when it is locked and when it is taken out of service. That reliability depends partly on the mechanics, but even more on human behavior. There are physical, psychological, procedural and regulatory steps that can and should be part of the whole sealing process.
Theft, smuggling, sabotage, and other nefarious activities are human behavior issues. They must be met with a flexible and unpredictable approach, by people who are as creative, determined and as skilled as the criminals who carry out such acts. Relying too much on technology without addressing the human factors and realities of the situation will not get the job done.
Standards and techniques to improve application
Who is handling the seals (and how) is what matters most. Seals are used to great benefit in countless applications every day. One can argue which ones work best (or don’t work) for a given use, or even if they are necessary for your purposes. But, if you use security seals, it is more important to deal with how they will be handled. This is primary and helps determine the type of seal that fits your purpose.
For a seal to be effective there needs to be a real effort on the user’s part. Using tamper evident seals effectively is a far greater challenge than finding a design that fits.
Uncovering tampering of a seal requires a reasonable level of reliability when it is locked and when it is taken out of service. That reliability depends partly on the mechanics, but even more on human behavior. There are physical, psychological, procedural and regulatory steps that can and should be part of the whole sealing process.
Theft, smuggling, sabotage, and other nefarious activities are human behavior issues. They must be met with a flexible and unpredictable approach, by people who are as creative, determined and as skilled as the criminals who carry out such acts. Relying too much on technology without addressing the human factors and realities of the situation will not get the job done.
There are many techniques or “tricks” which will help to make a security seal more effective. All must be backed by real consequences and personal responsibility.
It is important that seal users are always evaluating and finding their own measures that will best enhance the seals’ worth. Outlined below are just some general steps that can be taken to make tamper evident seals useful and effective. These are some of the techniques in summary form which are worth considering.
Security Seals
