RAR3-p (Uncompressed) Hash

What is RAR3-p (Uncompressed)?

The **RAR3-p (Uncompressed)** hash format is derived from the proprietary **RAR5** archive format’s password-protection mechanism, introduced by WinRAR (version 5.0+) as an evolution of its predecessor, RAR4’s **RAR3** scheme. Structurally, it employs a **hybrid cryptographic workflow** combining **AES-XTS-256** for full-disk encryption (in RAR5) with a **password-based key derivation function (PBKDF)**—specifically, a **customized iteration of SHA-256** with a fixed iteration count (typically **10,000 rounds**) and no explicit salt in the original implementation. The format’s primary use-case lies in securing compressed archives, where the hash serves as a **password verification mechanism** for decryption, though it lacks the formal cryptographic rigor of standards like PBKDF2 or Argon2. Unlike traditional hash-based schemes, RAR3-p does not directly store a salted hash of the password but instead derives a **256-bit encryption key** from the password via a deterministic process, which is then used in AES-XTS for block cipher operations. This design prioritizes **performance over security**, as it avoids salted hashing entirely, making it susceptible to offline attacks.

The **RAR3-p** format is vulnerable to cracking due to its **predictable key derivation, lack of salting, and computational efficiency**, which enables optimized brute-force attacks. The fixed iteration count (10,000 SHA-256 rounds) is insufficient for modern hardware, as GPUs and FPGA-based password crackers (e.g., **Hashcat’s "rar5" mode**) can evaluate **millions of hashes per second** with minimal overhead. Without a salt, identical passwords produce identical derived keys, allowing attackers to **precompute rainbow tables** for common passwords. Additionally, the **deterministic nature** of the key derivation (password → SHA-256 → AES-XTS key) means that even if the iteration count were higher, the absence of a salt negates the purpose of PBKDF. Furthermore, the **AES-XTS mode itself**—while secure for authenticated encryption—does not mitigate weak passwords; the core vulnerability remains in the **password-to-key derivation**, which is optimized for speed rather than resistance against brute-force. These flaws render RAR3-p **effectively obsolete** for strong password protection, as even basic GPU clusters can crack short or common passwords in minutes.

Identifying RAR3-p (Uncompressed) 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 RAR3-p (Uncompressed), security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack RAR3-p (Uncompressed)

If you need to recover the plaintext password for a RAR3-p (Uncompressed) 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.