Sim Card Explorer ((top)) -

SIM Card Explorer — Feature Specification

3.1 Hardware Abstraction Layer (HAL)

• Supports PC/SC (winscard, pcsc-lite), serial (TTY for legacy readers), and virtual SIM emulators.
• Manages APDU transmission, T=0/T=1 protocols, and PPS (Protocol Parameter Selection).

What is a SIM Card Explorer?

A SIM Card Explorer is a software application (often paired with specific hardware) that allows a user to read, write, analyze, and manipulate the data stored on a Subscriber Identity Module (SIM) card.

Unlike your smartphone’s native "Contacts" app, which only shows a fraction of the SIM’s data, an explorer software accesses the raw file tree of the card. This includes:

• EF-ADN (Abbreviated Dialing Numbers): Your phonebook.
• EF-LND (Last Number Dialed): The call history logs.
• EF-SMS: Stored text messages.
• EF-ICCID: The unique serial number of the card.
• EF-IMSI: The International Mobile Subscriber Identity (your network ID).
• ADM/Ki Keys: The authentication keys used to connect to cell towers (usually locked).

5. SIM Card Explorer (Mobile Apps - Android)

Best for: On-the-go viewing. Apps like SIM Card Manager or SIM Tool Manager on Android act as mobile explorers. While they lack the low-level hex editing of PC software, they are great for reading the card if you don't have a USB reader handy.

8. Evaluation & Limitations

In test runs with six commercial SIM cards (three GSM, two 4G USIM, one M2M), a prototype Explorer successfully: sim card explorer

• Read and decoded ICCID, IMSI, SPN, SMSC numbers.
• Retrieved up to 250 phonebook entries from EF_ADN/EF_PBR.
• Extracted all SMS messages (including hidden deleted ones still present in cyclic buffer).
• Identified two SIMs with an undocumented EF for roaming counters.

Limitations:

• Cannot access files behind CHV2/ADM without keys.
• Some operators use proprietary file IDs not in public standards.
• Java Card applets (SIM Toolkit) are not decompilable – only selectable.
• 5G SIMs with ISIM and additional security (mutual authentication) require new parsers.

Legal and Ethical Considerations

Warning: Using a SIM Card Explorer on a SIM card that does not belong to you is illegal in most jurisdictions under the Computer Fraud and Abuse Act (CFAA) in the US, or GDPR regulations in Europe.

You may only use these tools on:

1. Your own SIM card.
2. A company-owned SIM card with written authorization.
3. Evidence obtained via a warrant or subpoena.

Furthermore, attempting to extract the Ki (Authentication Key) to clone a SIM card for cellular fraud carries serious felony penalties (up to 20 years in prison in the US for wire fraud).

The Future: eSIM and the Death of the Physical Explorer?

The rise of eSIM (Embedded SIM) poses an existential question: Do we need a SIM Card Explorer anymore?

With an eSIM, the chip is soldered to the phone's motherboard. You cannot physically remove it and plug it into a USB reader. However, software-based eSIM explorers are emerging. These are apps that interface with the phone’s secure enclave to achieve the same result: reading the eSIM profile, backing up the activation code, or switching between profiles. SIM Card Explorer — Feature Specification 3

While the hardware "card" format is fading, the concept of exploring the SIM remains vital. Tools like EasyLPAC (for eSIM LPA) are the spiritual successors to the physical SIM Card Explorer.

4.4 Access Conditions & PIN Block

Access conditions are encoded in the FCP. An Explorer must:

• Request PIN verification (VERIFY CHV1) before reading files marked CHV1.
• Never attempt exhaustive search.
• Clearly warn user if a file requires ADM (Administrative) level – typically unavailable without manufacturer key.