The Fraud Prevention Source

Security Ink Authentication

Many types of inks can be used to print information on instruments like bank checks, tickets, identification and transaction cards, packages and labels, as well as other objects. Some inks are used for security reasons - to make it more difficult for fraud perpetrators to create counterfeit and altered objects that look authentic.

Some security inks, like certain fluorescent inks, can be purchased by anyone; other security inks are unique and are not sold because they are used only by the ink's developer; and other security inks can be purchased only by known commercial printers.

The existence of some security inks can be verified electronically and visually; others can be verified electronically without human intervention; and other inks can be verified visually without electronic assistance.

Let’s look at how security inks are used and how their existence can be verified.

Security Inks and Authentication

• a bank check before the bank check is paid.
• a ticket before the ticket is accepted.
• a product before the product is sold.
• an ID card before it is accepted as legitimate.
• any other object before that object is accepted as authentic.

Here are a few examples.

Magnetic inks contain components which can be detected by Magnetic Ink Character Recognition equipment (MICR Readers). For example the numbers that appear on the bottom line of all bank checks and many other financial instruments are printed with magnetic ink. Because of this the numbers can be read electronically by MICR Readers - hand-held devices or part of high-speed document processing systems.

A fraud perpetrator might create a counterfeit bank check by scanning the printed information on a bank check into a computer, then altering the dollar amount of the scanned bank check and finally printing what appears to be a perfect counterfeit check. However if the counterfeiter’s ink does not contain sufficient magnetic properties the MICR reader will unable to read the information printed on the bottom line of the counterfeit check.

If bank check information that should be printed with magnetic ink cannot be read by a MICR reader then it’s possible that the information was created by a counterfeiter who did not use magnetic ink. Thus if a MICR reader cannot capture information that should be printed with magnetic ink then the bank check failed an authentication test and is assumed to be counterfeit.

Fluorescent inks which are invisible cannot be seen without the use of an ultraviolet light ('black light'). Information printed with these invisible fluorescent inks cannot be copied or scanned by copy machines or scanners because the machines cannot detect the information printed with the invisible fluorescent ink.

Thus if a counterfeiter attempts to negotiate a copy of a financial instrument that does not contain the expected information printed with invisible fluorescent ink, then the counterfeit financail instrument will not pass the authentication tests.

In addition if information printed with invisible fluorescent ink (or information printed over fluorescent ink) is altered, a smudge or distortion can be seen under 'black light' even though the smudge or distortion may not be visible without use of a ‘black light’.

Activating inks can change color, show hidden information or similarly change appearance when an action such as scratching with a coin or fingernail or the application of another ink or chemical takes place. For example a code, such as 7459, might be invisible until the activating chemical is applied with a special felt pen and then the code 7459 will be visible.

Information printed with these activating inks cannot be copied or scanned by copy machines or scanners because the machines cannot detect the ink’s presence.

If a counterfeiter attempts to negotiate a copy or counterfeit of an original instrument that was produced with an activating ink it will not pass authentication because it will not contain the activating ink.

Thermochromic inks change color or appearance when there is a change in temperature. For example if a person holds his or her thumb on an area printed with thermochromic ink the temperature of the area under the thumb will change and that should cause a change in the color of the ink.

If a document that should contain thermochromic ink does not pass the "change in temperature, change in color" test it can be assumed that the document is counterfeit.

Optically Variable inks change color depending on the angle at which they are viewed. Printed information might appear to be green at one angle but look black at another angle.

If a document that should contain optically variable ink does not pass the "view at angle" test it can be assumed that the document is counterfeit.

Other Security inks are also created with detectable properties that can be authenticated. Some inks may contain a single property that can be easily detected while other inks may contain multiple properties that require extensive laboratory testing for a complete authentication. In some cases there may be the opportunity for immediate authentication with a more complete authentication only after extensive laboratory work.

DNA is often used for security. The DNA may be based on actual DNA or synthetic DNA. There are many different possible sequences of any DNA’s four base pairs (represented by A, C, T and G) and this provides security because it is virtually impossible to guess the base pair sequence of a DNA segment. For example there are over 1 billion different possible combinations of A, C, T and G in a DNA sequence that is only 15 base pairs long.

There are other security inks that contain a number of invisible colors that can only be seen with special equipment and/or analysis. These colors can be arranged in any order or sequence and so it is virtually impossible to guess the order or sequence of the colors contained in the security ink. The number of possible color combinations depends on the number of colors used in the ink relative to the number of possible colors that can be used in the ink.

Some inks cannot be seen without the use of infrared light and they provide security like invisible fluorescent inks that can be seen with ultraviolet light. In some cases inks that have already been used for printing information, are treated with chemicals and this creates a security that can be authenticated.

In short there are many types of security inks being used today and new inks will continue to be developed, manufactured and used for security. But, the basic authentication assumption is the same for all the inks - if the ink is not present an assumption of counterfeit is made.

Ethent Views

2) Producing a counterfeit, which might pass authentication, is more difficult if there is security ink because fraud perpetrators must acquire the correct security ink before they can attempt to create a counterfeit which might pass authentication.