The Mifare Classic RFID card is fundamentally just a memory storage device, where the memory is divided into segments and blocks with simple security mechanisms for access control. They are ASIC based and have limited computational power. Thanks to their reliability and low cost, these cards are widely used for electronic wallet, access control, corporate ID cards, transportation or stadium ticketing.
The Mifare Classic 1k offers 1024 bytes of data storage, split into 16 sectors; each sector is protected by two different keys, called A and B. They can be programmed for operations like reading, writing, increasing value blocks, etc. Mifare Classic 4k offers 4096 bytes split into forty sectors, of which 32 are same size as in the 1K with eight more that are quadruple size sectors. Mifare Classic mini offers 320 bytes split into five sectors. For each of these card types, 16 bytes per sector are reserved for the keys and access conditions and can not normally be used for user data. Also, the very first 16 bytes contain the serial number of the card and certain other manufacturer data and are read only. That brings the net storage capacity of these cards down to 752 bytes for Classic 1k, 3440 bytes for Classic 4k, and 224 bytes for Mini.
The simplicity of the basic cards means that they are inexpensive, which is largely the reason for their success in large-scale deployments.
Low-cost ICs that employ the same protocol as Mifare Classic, but without the security part and slightly different commands.
Mifare Ultralight C
The first low-cost ICs for limited-use applications that offer the benefits of an open 3DES cryptography.
Mifare Classic (Standard)
Employ a proprietary high-level protocol instead of ISO/IEC 14443-4, with an NXP proprietary security protocol for authentication and ciphering.
Drop-in replacement for Mifare Classic with certified security level (AES 128 based).
Are smartcards that comply to ISO/IEC 14443-4 with a mask-ROM operating system from NXP.
Mifare Prox, Smartmx
Are NXP Semiconductors brand names for smartcards that comply to ISO/IEC 14443-4.