A stylized credit card reader with "stealing" displayed on the reader and a credit card next to it. - Credit:Zain bin Awais/PCMag Composite;Aleksandra Konoplia/Talaj ...

Almost every weekday morning for the past year, I've been tapping my credit card for my morning coffee without thinking twice. What I didn't realize was that I was throwing money away. My card offers ...

All mainstream credit card numbers obey a mathematical trick designed to catch the most common typos. It’s called the Luhn algorithm, named after IBM researcher Hans Peter Luhn, who patented it in ...