Electrum Wallet (Salt-Type 4) Hash

What is Electrum Wallet (Salt-Type 4)?

The **Electrum Wallet Salt-Type 4** hash format is a legacy cryptographic scheme derived from the **SHA-256** algorithm, specifically tailored for Bitcoin address derivation in older versions of the Electrum client (pre-3.0). Introduced as a transitional measure to address vulnerabilities in earlier address generation methods (e.g., plain SHA-256 hashing of public keys), this format incorporates a **salted double-hash** structure to mitigate basic collision attacks. The process begins with the **public key** (uncompressed or compressed) being hashed twice with SHA-256: first with a **fixed salt** (a 32-byte nonce embedded in the Electrum protocol) and then again without modification. The resulting 64-byte hash is truncated to 20 bytes (160 bits) via a leftmost byte selection, producing the **RIPEMD-160** equivalent used in legacy Bitcoin address generation. This method was primarily deployed to prevent trivial replay attacks and address format inconsistencies in early Electrum implementations, though it retained the same vulnerability profile as standard SHA-256 hashing for private key recovery.

The **Salt-Type 4** format is cryptographically insecure due to its reliance on **predictable salts** and **inefficient collision resistance**. The fixed 32-byte salt, while preventing trivial collisions, is **not entropy-rich**—it is derived from the Electrum protocol version and client metadata, making it susceptible to **precomputed table attacks** (rainbow tables) if private keys exhibit low entropy. Additionally, the **double-hashing process** does not significantly improve security beyond SHA-256 alone; modern hardware (GPUs/ASICs) can brute-force 256-bit keys at rates exceeding **10¹⁸ hashes per second**, rendering brute-force attacks feasible for weak keys. The absence of **key stretching** (e.g., PBKDF2, scrypt, or Argon2) means that even minor optimizations—such as **parallelized GPU cracking** or **FPGA/ASIC acceleration**—can reduce recovery times from years to days. Furthermore, the **truncation to RIPEMD-160** introduces **length-extension vulnerabilities** if improperly implemented, though this is mitigated in Electrum’s context. The format’s obsolescence stems from its **lack of post-quantum resistance** and **inefficient resistance to GPU-optimized attacks**, rendering it unsuitable for modern cryptographic standards.

Identifying Electrum Wallet (Salt-Type 4) 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 Electrum Wallet (Salt-Type 4), security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack Electrum Wallet (Salt-Type 4)

If you need to recover the plaintext password for a Electrum Wallet (Salt-Type 4) 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.