These are Mifare 1K Classic Cards.
Being sold at throwaway prices.
These cards were pre – printed, but were not used thereafter. Hence they have been coated with a deep color. The chip and protocol is fully usable. However they cannot be printed by thermal (Dye – Sublimation) Technology.
Type of Cards :
employ a proprietary protocol compliant to parts (but not all) of ISO/IEC 14443-3 Type A, with an NXP proprietary security protocol for authentication and ciphering.
The MIFARE Classic card is fundamentally 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, those cards are widely used for electronic wallet, access control, corporate ID cards.
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. Each key can be programmed to allow operations such as reading, writing, increasing value blocks, etc. 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 MIFARE Classic 1K, .