Understanding the Timeframe for Cracking Modern Hashing Algorithms
Passwords serve as the first line of defense against unauthorized access, making their security crucial. While password recommendations now emphasize length over complexity, hashing remains essential. Even the most secure passphrases should be hashed to prevent exposure in the event of a data breach.
This article explores how cybercriminals crack hashed passwords, evaluates popular hashing algorithms, and offers strategies to strengthen password security.
Modern Password Cracking Techniques
Hackers utilize various methods to crack hashed passwords, leveraging high-powered computing resources. The most common techniques include:
1. Brute Force Attacks
Brute force attacks involve systematically guessing passwords by testing all possible combinations. With specialized software and GPU-powered hardware, attackers can generate millions of guesses per second. Although unsophisticated, this method is highly effective against weak passwords.
2. Password Dictionary Attacks
A dictionary attack uses precompiled wordlists, including common passwords, leaked credentials, and word variations (e.g., replacing "a" with "@"). This approach speeds up the cracking process by focusing on commonly used passwords instead of attempting random guesses.
3. Hybrid Attacks
Hybrid attacks combine dictionary-based methods with brute force techniques. Hackers take common words and modify them with numbers and special characters, making the attack more adaptive and efficient.
4. Mask Attacks
Mask attacks optimize brute force attempts by leveraging known password patterns. For instance, if an attacker knows that a password starts with a capital letter and ends with a number, they can significantly reduce the number of guesses required to crack it.
How Hashing Algorithms Defend Against Attacks
Hashing algorithms play a crucial role in securing passwords. Unlike plain-text storage, hashed passwords make it difficult for attackers to extract usable credentials. However, the effectiveness of a hashing algorithm depends on its complexity and resistance to brute force methods.
Can Hackers Crack Hashing Algorithms?
While hashing is a one-way function, attackers can still attempt to crack hashed passwords using brute force techniques. Popular tools like Hashcat, John the Ripper, and L0phtCrack enable large-scale cracking attempts, but the success rate depends on the hashing algorithm used.
The following benchmarks demonstrate how long it takes to crack different hashing algorithms using an Nvidia RTX 4090 GPU and Hashcat software:
1. MD5
Once considered a robust hashing algorithm, MD5 is now outdated due to its vulnerabilities. Despite its weaknesses, MD5 remains widely used—WordPress, for example, still relies on it by default.
Numeric passwords (13 characters or fewer): Instantly cracked
11-character passwords (alphanumeric & symbols): 26,500 years
2. SHA256
SHA256, part of the Secure Hash Algorithm 2 (SHA-2) family, is a widely used hashing function designed for security applications. Although stronger than MD5, it remains susceptible to brute force attacks on weak passwords.
9-character passwords (numeric or lowercase only): Instantly cracked
11-character passwords (alphanumeric & symbols): 2,052 years
3. Bcrypt
Bcrypt enhances password security by incorporating salting and a configurable work factor, making it highly resistant to brute force and dictionary attacks.
8-character passwords (alphanumeric & symbols): 27,154 years
Numeric or lowercase-only passwords under 8 characters: Cracked within hours to seconds
How Do Hackers Bypass Hashing Algorithms?
Regardless of the algorithm used, weak passwords remain the biggest vulnerability. Attackers often bypass hashing security by exploiting:
Short and simple passwords – Easily cracked with brute force techniques.
Password reuse – Stolen credentials from previous breaches are often valid for other accounts.
Exposed databases – Hackers frequently acquire pre-hashed passwords from data breaches, allowing them to test for weak hashes offline.
Protecting Against Password Cracking
To mitigate the risk of password cracking, organizations and users should:
Use long, complex passwords incorporating uppercase and lowercase letters, numbers, and special characters.
Implement multi-factor authentication (MFA) for additional security layers.
Regularly update password policies and enforce the use of strong, unique passwords.
Leverage password managers to generate and store secure credentials.
Monitor for leaked credentials using services like Specops Password Policy, which scans Active Directory against a growing database of over 4 billion compromised passwords.
By prioritizing strong password security and modern hashing techniques, organizations can significantly reduce the risk of password cracking and cyber threats.