So this comes up every time the US starts to approach the way credit and debit cards are processed in the rest of the world.

EMV (Euro/Master/Visa) defines the standard for a chip card. [1]

The cards can be configured as chip+signature, chip+pin or both. The priority ordering can be pin only, sig only, pin then sig or sig then pin (and a bunch of other esoteric rules).

Paywave (VISA) and Paypass (Mastercard) are contactless standards for EMV transactions.

The rules for chip+pin transfer the liability to the merchant (and the merchant bank) for fraudulent use. The liability moves from the card issuing bank. It's a "stick" to make the merchants upgrade. That's why merchants are going to at least chip+signature (ie EMV chip reduces fraud). Moving to chip+PIN reduces fraud even further.

The card issuing banks tend to introduce rules about how safe your PIN is and apply rules to your PIN to stop things like repetitive numbers (eg all 1s), sequences, birthdate matches etc.

Chip + PIN was introduced in the EU and other more advanced than the US banking environments (ie, everywhere) a number of years ago. The "liability shift" for Mastercard happened ~2006, Visa was ~2010, later in some places (eg AU was 2015).

It is only just happening in the US (according to Wikipedia it will be completed by 2020-10-01).

Paywave/Paypass implement new rules on when a PIN is required. In AU it is $100. If the amount is below that, then the liability is accepted by the merchant bank (ie the merchant will get paid). If it is >$100, then a PIN is required for the merchant bank to accept the transaction.

In Australia, if you report your card lost/stolen, then you are not responsible for Paywave/pass transactions. If you don't ("an unreasonably long time"), then you are, unless the card issuer (your bank) can chargeback the merchant (ie <120 days).

This applies to the Credit Card networks (Amex/MC/VISA/Discover/JCB/Union etc). MC and Visa also have "debit" cards that use the same network and are treated basically the same for the merchant.

There are other payment networks (eg in AU there is EFTPOS) which is an AU bank owned network that basically does direct debit from cardholder to merchant online. So if you actually insert your card in the reader, you'll get the choice of "CR" (ie the MC/VISA network, SAV (EFTPOS) or CHQ (EFTPOS)).

So an "ANZ Bank Mastercard" can have 3 different accounts attached, the Mastercard CC account, and two different savings accounts. No one really has a "cheque" account anymore. The banks also issue Mastercard/VISA debit cards (that also offer CC/SAV/CHQ, but CC actually means SAV) and their own debit cards (EFTPOS only).

EFTPOS has much lower fees for both merchants and the banks. That's why Apple Pay hasn't been accepted yet by 3 of the 4 major AU banks, because they don't want to lose their sweet EFTPOS network or pay more to MC and VISA. They also don't want to pay Apple (or Google) more fees in the interchange.

For a while, supermarkets were making people with MC/VISA debit cards insert their cards and only allow them to use the SAV/CHQ options so that they didn't have to pay CC transaction fees for EFTPOS debit transactions.

Anyway, the summary of all this is that moving the US away from signatures is painful because of the disjointed and irrational US banking and payment systems as well as the baked in insistence by users on signatures and paper checks (not cheques, 'cos nowhere that spells it correctly still uses them much :) ).

[1] https://en.wikipedia.org/wiki/EMV