What is the difference between RFID standards?

Question

Electronics

Hey!
I read a lot about RFID, a lot of questions arose.
1. What is the difference between standards and frequencies?
RFID 125kHz:
Em-Marine
ATMEL T5557
HID Prox
HID Indala
13.56 MHz
NXP Mifare family
HID iClass
2. How well protected are the cards? Why is it impossible to copy a metro card and ride on someone else's, because in fact the number is attached to the card and all
3. How reliable is it to use ACS on RFID cards? If I put a lock on the second door of the house and open it using the map, will they be able to copy the label?
4. Something in the articles flashed about DES, 3DES and RSA encryption, but it is not entirely clear what and where is encrypted there

Answer 1

The question is too general.
To do this, you need to open the standards and compare.
Standards and frequencies are different concepts.
Depends on the card.
In fact, not only the number is attached to the travel card.
Depends on the task.
Hang up. Certainly.
Some cards can record information, and the cards can encrypt it.

Answer 2

Hi Mark. If you had a specific task, then probably you would not be primarily interested in the difference between all these standards. I worked closely with the NXP Mifare family, and as far as I know, metro tickets are also of this family. Within the standard itself, there are various types of cards, but in relation to them it is already interesting to understand their features, for example, how Mifare UltraLight differs from Mifare Plus S. For example, UL simply contains memory areas that are accessible by key, but Plus S already contains encrypted areas and can work like a real smart card. There is also Mifare Classic, etc.
Plus S is secure enough to use even as a bank card.

Answer 3