Episode 3: What will it take to make currency notes hard to counterfeit

(Lightly edited for readability)

Speakers

Bipin Kumar Gupta, Arpan Banerjee, Amrita Gupta, Subhra Priyadarshini

00:08 Subhra Priyadarshini: Welcome to the Nature India podcast from New Delhi, India. This is Subhra Priyadarshini.

00:15 Amrita Gupta: And I'm Amrita Gupta.

00:18 Subhra Priyadarshini: This episode we're talking science and money. In November 2016, India rolled out a massive demonetisation exercise, in part to root out counterfeit cash. Can science stop counterfeiting? We speak to two scientists to understand what it will take to make India's currency notes harder to copy.

00:43 Bipin Kumar Gupta: You can see? In 254 it’s going red. Can you see? Now pressing this 365. Now can you see a green color? Can you see?

00:56 Amrita Gupta: That's Bipin Kumar Gupta, a scientist working on luminescent materials and devices. The glowing colors he's showing us a security inks that he synthesised at the National Physical laboratory in New Delhi. When these inks are excited by particular wavelength, they glow, bright red and bright green. Gupta said he spent seven years working on these formulas.

01:21 Bipin Kumar Gupta: So 10 (times) successively, we changed the pigment and changed the medium. And ultimately now we are in the stage, we make very, very strong kind of pigment that can be hard to counterfeit….to make this kind of development to stop the duplication of the, you know, currency or duplication of the stamped paper or duplication of the, like very important documents. So many important places these kinds of pigments are used for the protection of the counterfeiting.

01:51 Subhra Priyadarshini: Counterfeiting is a serious threat to the economy. The Indian Statistical Institute in Kolkata estimates that 70 crore or 700 million rupees worth of fake Indian currency notes enter the system every year.

02:07 Amrita Gupta: Gupta says his bioluminescent inks made by combining nanorods of rare earth elements with light emitting inorganic solids will help curb that. We asked him to explain.

02:20 Bipin Kumar Gupta: Normally the tradition of the, you know, security or luminescence, I think, not only in India, but worldwide they are using the like single colour excitable and single emission kind of the security ink and it's a broad excitation range. So easy to counterfeit it. But our study is different. So our luminescent pigment, which we have developed here, it can excite with the two colours.

02:48 Amrita Gupta: These inks are non-toxic, and their pigments can be synthesised at high yields, he told us and they're highly luminescent. Basically brighter than what's used in most currencies today. Banknotes around the world are packed with security features, not just luminescent inks, but holograms watermarks, optically variable ink known as OVI. That's why the colour shifts depending on the angle you're looking at it from. Governments spend millions on these security features. But whether it's the rupee or the Euro, or the dollar, the thing is counterfeiting is still rampant.

03:25 Subhra Priyadarshini: Yeah, it's interesting, and the solution might not come from material science alone. In fact, a neuroscientist from Stanford University in California, David Eagleman says that understanding the brain is actually the key to tackling forgery. A note can be packed with security features, but the thing is, you and I don't pay attention to whether those features are there or not.

03:47 Amrita Gupta: We asked Arpan Banerjee to explain. He's an associate professor at the National brain research center. He spoke to us from his lab in Gurgaon.

03:57 Arpan Banerjee: For example, if I asked you in the lab, do you remember the signature of the person who signs, for example, the RBI governor, and most likely people won't be able to answer that question, but it is there in every note, we touch it every day. Exactly.

04:13 Amrita Gupta: Banerjee agrees with Eagleman research when he says that were surprisingly an observant we don't scrutinize the details in our banknotes, security features are not. And that comes down to something called salience.

04:28 Arpan Banerjee: Salience by the definition essentially means that how we understand if something is different from others. So for example, if some red object is present amongst a bunch of green objects, you don't really care about all the other green objects but you the red object that pops out immediately. So what he's talking about essentially comes from the neuroscience research that has been going on in this field that some things pop out and if you align the pop-out thing with your security device whatever, then it will pop out better, in a currency for example.

05:04 Amrita Gupta: The main reason we don't notice is because currency notes are jam packed with other elements. Indian notes have Mahatma Gandhi, the flag, the Ashoka emblem, many monuments, even Mangalyaan, the Mars space probe.

05:18 Arpan Banerjee: Basically, based on the Indian context, the note has to be regal, it has to be colorful. So given all things, can we design the best place in the note, and that's actually a neuroscience question.

05:32 Amrita Gupta: So what would it take to notice security features despite all this distraction?

05:37 Arpan Banerjee: I mean, ideally speaking, we should be going for more simple things. So in a way, this is the same principle that David Eagleman is talking about, and that's why he goes on saying that ideally speaking, you should have a white piece of paper and only security features on the top of it. That way, everything pops out, right? Except that nobody will allow this.

05:59 Amrita Gupta: So given that the human visual system isn't built to detect forgeries at a glance, and that we aren't likely to declutter our notes anytime soon. What's the common man to do?

06:10 Subhra Priyadarshini: Currently, what happens is that fake notes tend to surface only at banks, which have the right equipment to detect them. Bipin Gupta is working on an LED based device that will help you and I quickly check if the note is real or not. He says, we'll just have to scan it with our mobile phones and we'll know.

06:29 Bipin Kumar Gupta: So our idea is very simple. If we can do something like very, very easy to detect and difficult to counterfeit and introduce it in the note, and it will be (suppose) indigenous, then (it will be) hard for the counterfeiter to counterfeit these kinds of the notes. And second thing is our country is importing a lot of these pigments not only for the bank notes, it's a lot of items like if you see the stamp paper, if you see the passport, if you see the, you know, postal orders. So, everywhere we require these kind of pigments to make security features. So if we can develop indigenously in India, like in the ‘Make in India’ programme, we have our own ink or letter, like our own security feature with our own priorities.

07:16 Amrita Gupta: His point about the inks, being indigenous is actually an important one. It costs a lot of money to print money. According to the Reserve Bank of India, 40% of that money goes towards importing paper and ink. And of course, relying on indigenous technology is also important for the country's own security. Gupta's lab has recently signed a contract with the Security Printing and Minting Corporation. So it's likely that Indian currency printed with ink made in India will find its way into our hands soon. For Nature India, this is Amrita Gupta.

07:53 Subhra Priyadarshini: Bipin Kumar Gupta looks all set to leave his mark. In this case, quite literally with his security inks. But even with more secure features on our currency notes, the question remains as Arpan Banerjee rightly points out whether we will pay enough attention to them or not.

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