KSEC Tagbase

Our RFID & NFC Knowledge Base

Version 1.3.1


IS23SC4439 Card,Compatible Mifare 1K Card

IS23SC4439 Card, ISSI4439 Card, Compatible Mifare 1K Card.


1K bytes EEPROM Contactless Smart Card Conform to ISO/IEC 14443A Standard

Contactless transmission of data and supply energy
Up to 100mm operation distance
13.56MHz operating frequency
106k bit/s date rate
High level security data communication
True anti-collision
1k bytes EEPROM, organized in 16 sectors with 4 blocks of 16 bytes each
User definable access condition for each memory block
Data retention > 10 years
Write endurance > 100,000 cycle
Typical ticketing transaction < 100ms
Three pass authentication (ISO/IEC DIS9798-2)
Data encryption on RF-channel with replay attack protection
Two keys per sector (per application) to support multi-application with key hierarchy
Unique serial number for each device
Transport key protects access to EEPROM on chip delivery
Conform to ISO/IEC14443A standard
Operation temperature range -25 to +70C

IS23SC4439 is contactless smart card IC compliant to ISO/IEC 14443A standard with 0.18um CMOS EEPROM process technology. IS23SC4439 has 1k bytes EEPROM. It has high performance security functions and contactless communication functions. IS23SC4439 can be used in payment card, public transportation card and many other applications.

Typical Transaction Time
Identification of a card: 2.5ms (incl. Answer to Request, Anticollision and Select)
Authentication: 2ms
Read block (16 bytes): 2.5ms (excl. Authentication)
Write block + Control Read: 4ms (excl. Authentication)
Typical ticketing transaction: < 100ms

Block Description
The IS23SC4439 chip consists of 1k bytes EEPROM, RF Interface and Digital Control Unit. Energy and data are transferred via an antenna, which consists of a coil with a few turns directly connected to the IS23SC4439. No further external components are necessary.

Data Integrity
To ensure reliable data transmission, following mechanisms are implemented in the contactless communication link between PCD and PICC:
16 bits CRC per block
Parity bits for each byte
Bit count checking
Bit coding to distinguish between “1″, “0″, and no information
Channel monitoring

To provide high secure level, the triple pass authentication according to ISO 9798-2 is used in the following sequence:
a. PCD specifies the sector to be accessed and chooses key A or B.
b. PICC reads the secret key and access conditions from the sector trailer, then PICC sends a random number as the challenge to PCD (pass one).
c. PCD calculates the Response using the secret key and additional input. The response, together with a random challenge from PCD, is then transmitted to PICC (pass two).
d. PICC verifies the response of PCD by comparing it with its own challenge and then calculates the response to the challenge and transmits it (pass three).
e. PCD verifies the response of PICC by comparing it to its own challenge.
Note: After transmission of the first random challenge the communication between PICC and PCD is encrypted.

RF Interface
The RF interface is according to the standard for contactless ISO/IEC 14443A compatible smart card. The carrier field from PCD is always present (with short pauses when transmitting). For both directions of data communication there is only one start bit at the beginning of each frame. Each byte is transmitted with a parity bit at the end. The LSB of the byte with the lowest address of the selected block is transmitted first. The maximum frame length is 163 bits.

Memory Organization
The 1024 x 8 bit EEPROM memory is organized in 16 sectors with 4 blocks of 16 bytes each. In the erased state the EEPROM cells are read logical “1″, in the written state as a logical “0″.

Memory Access
Before any memory operation can be carried out, PICC has to be selected and authenticated as described previously. The possible memory operations for an addressed block depend on the key used and the access conditions stored in the associated sector trailer.