Emmc Cid Decoder [cracked]

eMMC CID Decoder — Technical Report

2. Data Recovery

In logical data recovery, matching the correct CID to a disk image ensures integrity. Forensic analysts decode CIDs to verify that an image came from a specific physical device.

Part 2: How to Extract the CID from a Device

You cannot decode what you cannot read. Extracting the CID requires either software access (if the device is booted) or hardware access (if the device is dead or locked).

5. Implementation Example (Python)

def decode_emmc_cid(cid_hex):
    cid_bytes = bytes.fromhex(cid_hex)
    if len(cid_bytes) != 16:
        raise ValueError("CID must be 16 bytes")
mid = cid_bytes[15]
pnm = cid_bytes[11:7:-1][::-1].decode('ascii').strip()
prv_major = (cid_bytes[7] >> 4) & 0x0F
prv_minor = cid_bytes[7] & 0x0F
psn = int.from_bytes(cid_bytes[6:3:-1], 'big')
mdt_raw = (cid_bytes[3] << 8) | cid_bytes[2]
year = 2000 + ((mdt_raw >> 4) & 0xFF)
month = mdt_raw & 0x0F
return 
    "mid": hex(mid),
    "manufacturer": lookup_manufacturer(mid),
    "product_name": pnm,
    "revision": f"prv_major.prv_minor",
    "serial": psn,
    "date": f"year-month:02d"

Manufacturer lookup table based on JEDEC JEP106 (available in many open‑source projects). emmc cid decoder

Part 5: Interpreting the Decoded Output – A Case Study

Let’s decode a real CID from a SanDisk eMMC used in a Chromebook.

Raw CID: 45010053454d303447d301d4935400b2 eMMC CID Decoder — Technical Report 2

Decoded:

• MID: 0x45 (SanDisk/Western Digital)
• OID: 0x01
• PNM: "SEM04G" → SanDisk eMMC 4GB
• PRV: 0xD3 → Revision 13.3
• PSN: 0xD4935401
• MDT: 0xB2 → Year: 11 (2011), Month: 2 (Feb)

What this tells you: This chip is a 4GB eMMC manufactured in February 2011. If your device expects a 32GB eMMC, you now know it has been swapped. Additionally, an old manufacturing date suggests the chip may have worn-out NAND cells, explaining boot failures. Manufacturer lookup table based on JEDEC JEP106 (available

9. Recommendations

• Use the device datasheet for authoritative field definitions and CRC details.
• Implement CRC7 check when validating parsed CID.
• If collecting manufacturer names from MID, use an up-to-date registry.