Electrum Wallet (Salt-Type 5) Hash

What is Electrum Wallet (Salt-Type 5)?

The Electrum Wallet Salt-Type 5 cryptographic hash format is a legacy derivation scheme primarily used in older versions of the Electrum Bitcoin client (pre-2.0) to secure private keys through a deterministic but non-standardized hashing pipeline. Originating as an internal optimization to mitigate brute-force attacks on wallet backups, it combines a salted PBKDF2-HMAC-SHA256 iteration with a custom key-stretching mechanism. The structure begins with a 16-byte salt derived from the wallet file’s metadata (e.g., `x-wallet-ipc` or `storage` directory), followed by a 10,000-iteration PBKDF2-HMAC-SHA256 passphrase hash. This intermediate hash is then XORed with a fixed 32-byte seed (`ElectrumSalt5Seed`) before being fed into a second HMAC-SHA256 round with the original passphrase, producing a 64-byte master key. Unlike modern standards like BIP-39/BIP-32, this format lacks formal cryptographic scrutiny, relying instead on ad-hoc hardening to thwart weak passphrases. Its primary use-case was to encrypt wallet backups with a user-provided passphrase, enabling offline key storage while ostensibly resisting dictionary attacks through iterative hashing.

The Salt-Type 5 format is vulnerable to cracking due to three critical design flaws: **predictable salt reuse, insufficient iteration variability, and GPU-accelerated optimization**. The salt is not cryptographically random but derived from filesystem metadata, allowing attackers to enumerate possible salts via directory traversal or metadata leaks. Even with 10,000 PBKDF2 iterations, modern hardware (e.g., FPGA/ASIC clusters) can brute-force weak passphrases at rates of **100,000–1,000,000 hashes/second** per device, especially when combined with rainbow table precomputation. The absence of a per-key salt in the final HMAC round eliminates salt diversification, enabling attackers to precompute hashes for common passphrases offline. Additionally, the fixed seed (`ElectrumSalt5Seed`) and deterministic iteration count render the scheme susceptible to **collision attacks** and **side-channel exploitation**, as the hashing pipeline lacks adaptive resistance to parallelization. Unlike modern key derivation functions (e.g., Argon2), Salt-Type 5’s linear memory-hardness and lack of timing-based defenses make it trivial to deploy GPU-optimized cracking tools like Hashcat or custom CUDA kernels, reducing recovery times to minutes for short passphrases.

Identifying Electrum Wallet (Salt-Type 5) 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 5), 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 5)

If you need to recover the plaintext password for a Electrum Wallet (Salt-Type 5) 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.