JCOP Cards and Development

JCOP Cards and Development

JCOP (Java Card Open Platform) is NXP Semiconductors' family of smart card chips that implement the JavaCard and GlobalPlatform specifications on NXP's secure microcontroller hardware. JCOP chips are among the most widely deployed smart card platforms, found in banking cards, transit passes, ePassports, and identity documents worldwide.

Use the Card Identifier to identify a JCOP chip from its ATR.

JCOP Platform Generations

The J3R180 is the standard development card (180 KB EEPROMEEPROMHardwareNon-volatile card memory for data.Click to view →). The J3H145 adds a dedicated crypto coprocessor for hardware-accelerated ECDH and RSA operations.

JCOP Tools for Eclipse

NXP provides JCOP Tools as an Eclipse plugin for integrated simulation and on-card debugging. Installation:

1. Open Eclipse Marketplace: Help → Eclipse Marketplace.
2. Search for "JCOP Tools" and install the NXP JCOP Development Tools plugin.
3. Restart Eclipse. A new JCOP perspective appears.
4. Configure JCOP SDK path: Window → Preferences → JCOP Tools → SDK Location.

Key Eclipse views: - JCOP Simulator — software emulation of JCOP 4 environment. - Script Editor — send raw APDUs to simulator or physical card. - JCOP Debug — step-through JavaCard applet execution on simulator. - File System Viewer — browse the card's GP file hierarchy.

Creating a JCOP Project

File → New → JCOP Project
  ├── Select JCOP version: JCOP4 J3R
  ├── Package AID: D276000001
  └── Applet AID:  D27600000101

src/
  └── com/example/MyApplet.java

A minimal applet skeleton:

package com.example;
import javacard.framework.*;

public class MyApplet extends Applet {
    private byte[] buffer;

    private MyApplet(byte[] bArray, short bOffset, byte bLength) {
        buffer = JCSystem.makeTransientByteArray((short) 32, JCSystem.CLEAR_ON_DESELECT);
        register();
    }

    public static void install(byte[] bArray, short bOffset, byte bLength) {
        new MyApplet(bArray, bOffset, bLength);
    }

    public void process(APDU apdu) throws ISOException {
        if (selectingApplet()) return;
        byte[] buf = apdu.getBuffer();
        switch (buf[ISO7816.OFFSET_INS]) {
            case (byte)0x10:
                handleGetData(apdu);
                break;
            default:
                ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
        }
    }

    private void handleGetData(APDU apdu) {
        byte[] buf = apdu.getBuffer();
        buf[0] = (byte) 0xDE;
        buf[1] = (byte) 0xAD;
        apdu.setOutgoingAndSend((short) 0, (short) 2);
    }
}

JCOP Simulator vs Physical Card

Always test cryptographic timing and EEPROM wear patterns on physical hardware before finalising a design.

Key JCOP-Specific APIs

JCOP 4 extends the standard JavaCard API with NXP-proprietary packages:

Avoid proprietary APIs where JavaCard standard equivalents exist — they reduce portability to non-JCOP hardware.

Development Cycle

1. Write applet in Eclipse (JCOP project)
2. Test on simulator (debug APDU flow)
3. Build .cap file: ant or Gradle with ant-javacard
4. Load to physical card via GlobalPlatformPro:
      java -jar gp.jar --install MyApplet.cap
5. Run pyscard or pytest test suite
6. Profile EEPROM usage and crypto timing
7. Submit for CC / EMVCo evaluation (if required)

For loading and managing applets on JCOP cards, see the GlobalPlatform Pro Guide. For debugging techniques once the applet is running, see the Smart Card Debugging Guide. For setting up the full toolchain, see the Dev Environment Setup Guide.