Android PIN Hash

What is Android PIN?

The **Android PIN hash format** (introduced in early Android versions) is a cryptographic hash structure designed to securely store user-defined PINs for device unlock mechanisms. Originating from the need to protect sensitive credentials without exposing them in plaintext, this format leverages a **SHA-1-based** (later SHA-256 in some variants) hash of the PIN concatenated with a **static salt** (typically `"saltysalt"` or similar) and additional metadata like the **user ID**, **device serial number**, and **hash iteration count** (ranging from 1,000 to 4,000 iterations). The resulting hash is stored in the Android’s **keystore database** (`/data/data/com.android.providers.settings/databases/settings.db`) under the `secure` table, where it serves as a challenge-response mechanism during authentication. While this design aimed to mitigate brute-force attacks through computational overhead, its reliance on a **fixed salt** and predictable iteration schemes rendered it vulnerable to offline attacks once extracted from the device.

The Android PIN hash format is susceptible to cracking due to **several critical weaknesses**, primarily stemming from its **predictable structure and computational inefficiencies**. The **static salt** (e.g., `"saltysalt"`) allows attackers to precompute or reverse-engineer hashes offline using tools like **hashcat** or **John the Ripper**, especially when combined with **GPU/ASIC optimizations** for SHA-1/SHA-256 cracking. The **limited iteration count** (historically as low as 1,000) provides insufficient computational resistance, as modern hardware can brute-force 6-digit PINs (the default max length) in **minutes to hours** under optimized conditions. Additionally, the **lack of per-user salts** and **replayable hashing** (due to static metadata) enables **rainbow table attacks** and **cracking via extracted database dumps**, further exacerbating vulnerabilities. Finally, the **absence of modern cryptographic safeguards** (e.g., Argon2, PBKDF2 with high iterations, or hardware-backed key derivation) leaves it exposed to **side-channel attacks** and **timing analysis** if not properly mitigated by the OS.

Identifying Android PIN Hashes

Identifying a hash blindly is often difficult because multiple algorithms can output strings of the exact same length. For example, a standard 32-character hexadecimal string could be MD5, NTLM, MD4, or LM. To definitively identify Android PIN, security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack Android PIN

If you need to recover the plaintext password for a Android PIN hash during a penetration test or forensics investigation, you must supply the correct module ID to your cracking software. Use the exact commands provided at the top of this page to target the hash successfully.