The Power of Strong Passwords Against Brute-Force Attacks

By /

Listen to this Post

Featured Image
Brute-force attacks remain one of the most straightforward yet dangerous cyber threats. Attackers use tools like Crunch, Hydra, and John the Ripper to generate and test password combinations. However, a well-constructed password can render brute-force attempts useless.

Understanding Brute-Force Math

  • Alphanumeric combinations (a-z, A-Z, 0-9): 62 possible characters.
  • Password length vs. combinations:
  • 12 characters: 3.2 × 10²¹ possibilities (years to crack: ~1 trillion).
  • 18 characters: 8.46 × 10³⁰ possibilities (storage needed: ~11,785 PB).

You Should Know: Practical Password Security

1. Generating Strong Passwords

Use OpenSSL or Python to create random passwords:

 Linux (OpenSSL) 
openssl rand -base64 16

Python 
python3 -c "import secrets; print(secrets.token_urlsafe(16))"

2. Testing Password Strength with Crunch

Crunch generates wordlists for brute-force testing:

crunch 12 12 -t %%%%%%%%%%%% -o 12chars.txt  12-char alphanumeric 
crunch 18 18 -f /usr/share/crunch/charset.lst mixalpha-numeric -o 18chars.txt

Optimize storage with `-d` (limit repeating chars):

crunch 12 12 -d 2 -t %%%%%%%%^%%% -o reduced_list.txt

3. Cracking Hashes with Hashcat

Test password resilience against common hashes:

 MD5 (Fast) 
hashcat -m 0 -a 3 hashed_passwords.txt ?a?a?a?a?a?a?a?a

NTLM (Windows) 
hashcat -m 1000 -a 3 ntlm_hashes.txt ?a?a?a?a?a?a?a?a?a

bcrypt (Slow, resistant) 
hashcat -m 3200 -a 3 bcrypt_hashes.txt -O -w 3

4. Defending Against Brute-Force

  • Rate-limiting login attempts (e.g., `fail2ban` on Linux).
  • Multi-Factor Authentication (MFA) (google-authenticator for SSH).
  • Password salting & strong hashing (Use Argon2 or bcrypt).

What Undercode Say

Brute-force attacks are ineffective against long, random passwords (16+ chars). However:
– Weak hashes (MD5, NTLM) accelerate cracking.
– GPU clusters reduce cracking time drastically.
– Password reuse remains a critical vulnerability.

Key Commands for Security Testing:

 Check password strength with CrackLib 
echo "Password123" | cracklib-check

Simulate brute-force with Hydra 
hydra -l admin -P wordlist.txt ssh://192.168.1.1

Secure Linux passwords with PAM 
sudo nano /etc/pam.d/common-password  Set `minlen=12` and `ucredit=-1`

Expected Output: A secure system enforces long passwords, MFA, and rate-limiting while avoiding weak hashing algorithms.

Further Reading:

References:

Reported By: Cyberflood Crunch – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

Join Our Cyber World:

💬 Whatsapp | 💬 Telegram

Related Posts: