sha1($salt.unicode($pass)) Hash

What is sha1($salt.unicode($pass))?

SHA-1 was originally designed as part of the SHA (Secure Hash Algorithm) family by the NSA in 1993, standardized as FIPS 180-1 in 1995, and intended for digital signatures, message integrity verification, and lightweight cryptographic applications. The format `sha1($salt.unicode($pass))` represents a hashed password storage scheme where the plaintext password (`$pass`) is first converted to Unicode (typically UTF-8), concatenated with a cryptographic salt (`$salt`), and then processed through the SHA-1 hashing algorithm. This structure was widely adopted in early web applications (e.g., PHP’s `crypt()`-like implementations) to mitigate rainbow table attacks by ensuring uniqueness per user via per-password salts. SHA-1’s 160-bit (20-byte) output provided a balance between computational efficiency and collision resistance at the time, though its design lacked iterative slowing mechanisms like those in bcrypt or PBKDF2.

The vulnerability of this scheme stems from SHA-1’s inherent weaknesses and implementation flaws. SHA-1’s 160-bit output is now considered insecure due to practical collision attacks (e.g., SHA-1 has been broken in ~2²⁵⁶ operations), rendering it unsuitable for cryptographic purposes. The format’s reliance on a salt only prevents rainbow table attacks but offers no resistance to brute-force or GPU-optimized cracking (e.g., via tools like Hashcat), as SHA-1’s compression function allows for parallelizable, high-speed hashing. Additionally, the lack of iterative hashing (e.g., no built-in work factor) enables attackers to evaluate millions of passwords per second on modern hardware, rendering it vulnerable to dictionary and hybrid attacks. The Unicode conversion also introduces potential encoding inconsistencies, and the absence of key stretching exacerbates the risk of offline cracking.

Identifying sha1($salt.unicode($pass)) 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 sha1($salt.unicode($pass)), security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack sha1($salt.unicode($pass))

If you need to recover the plaintext password for a sha1($salt.unicode($pass)) 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.