[II2II]

I was going to say such advice does have its limits. Then I remembered something: even though my current credit card does have a chip, the design suggests that it is primarily intended as a record of a "user id" and "password" (e.g. large easy to read numbers, rather than the embossed numbers intended to make impressions upon carbon copy forms that typically became impossible to read with wear).

[j16sdiz]

Not exactly. Some transactions are cryptographically authenticated. "The algorithm" looks at those bits. Transactions with proper chips authentication are less likely to be flagged as fraud

[viraptor]

Also the embossed numbers are not that common in countries outside the US. For quite a while the numbers themselves are also disappearing from the front. (If you even use the physical card rather than your phone)

[bboygravity]

I remember being mind-blown on my first trip to the US when a taxi driver took my card and literally carbon copied it manually (with a pencil and carbon copy booklet) on the spot.

I had been using my credit card for at least a decade (Europe) and it never ever occured to me that the embossed letters had any function other than aesthetic.

And the cheques... jaw drop

[robin_reala]

That is how they used to work though. I’m old enough to remember imprinters, which literally used the embossed numbers to create a carbon copy: https://en.wikipedia.org/wiki/Credit_card_imprinter

[Zanfa]

I had a food delivery guy use one in the US 2012/2013. It was like seeing a native tribe perform their traditional dance. It still blows my mind that chip + "signature" is a thing in the US. What good is a random indiscernible scribble on a tiny resistive touch screen as far as proving anything?

[staunton]

It's quite illegal to fake signatures so it acts as a deterrent. I can't think of anything else...

[chgs]

That was how things worked back in the 80s and 90s, online or chip systems were in place 20 years ago in Europe