Transcript for Digital Pickpocketing
We're going to turn next tonight to a consumer alert for millions of holiday shoppers. Those tiny new chips in so many of our credit cards, holding our personal information. They're supposed to be more secure. ABC's Rebecca Jarvis now with the eye opening demonstration. Reporter: Holiday season is primetime for bargains. But as you're eyeing those kis counts, centimeters may be eyeing you. My last offer, $4 million. Reporter: Robert her Ja vehicle is also a cyber security expert and shows us the brand new way hackers can quickly steal your credit card information. Watch. My wallet right next to me. He just rests his phone on top and seconds later, he has my credit card number, history of all my transactions, even my pin. This is pretty simple. We staged this, but really, I mean, this is reality. You're busy. You don't know what's going on. It is easy for somebody to take that. Reporter: He says it could happen to most credit cards with smart chips. By the end of next year, 70% of credit cards in the united States are expected to have them. These smart cards are safer than traditional cards, but hackers are still one step ahead. How do you protect yourself? Read your entire credit card line by line. Reporter: So, be on alert. Check your credit card statement for small charges. I'm not going to go buy a $5,000 item. I'm going to spend $20 or $100. Reporter: Those little microcharges. Yep, we call that microfraud. Reporter: And he says there's a solution in your kitchen. Wrap the card in aluminum foil. Tinfoil works? It works. Reporter: A low tech fix to a high tech problem. Rebecca Jarvis, ABC news, new York. Wow, aluminum foil. Thank you.
This transcript has been automatically generated and may not be 100% accurate.