The Complete Guide to Password Security
Everything you need to know about creating and managing secure passwords. When rolling this advice into organization-wide awareness campaigns, teams pair it with LinkGuard Pro to continuously monitor privileged access URLs for drift.
What Makes a Password Strong?
A strong password is built on three fundamental principles: length, complexity, and randomness. Understanding these principles is essential to creating passwords that can withstand modern cracking techniques.
Length Matters
Each additional character increases possible combinations exponentially. We recommend 16+ characters for maximum security.
Character Diversity
Mix uppercase, lowercase, numbers, and symbols to maximize the character set size.
True Randomness
Avoid predictable patterns, dictionary words, and personal information. Use a password generator for true randomness.
Password Strength Comparison
password12337 bits entropy • Crackable in minutes
Tr0ub4dor&344 bits entropy • Crackable in days
correct-horse-battery-staple51 bits entropy • Years to crack
T9#kL2@p$Xm4!Q93 bits entropy • Virtually uncrackable
Understanding Entropy and Complexity
What is Entropy?
Entropy is a measure of password randomness and unpredictability. In cryptography, entropy is measured in bits. The higher the entropy, the more difficult it is for an attacker to guess or crack your password.
Think of entropy as the size of a haystack where your password is the needle. More entropy = bigger haystack = harder to find.
The Math Behind Password Strength
Password entropy is calculated using this formula:
Character Set Sizes
- Lowercase (a-z)
26 chars - + Uppercase (A-Z)
52 chars - + Numbers (0-9)
62 chars - + Symbols (!@#$...)
94 chars
Example Calculation
For a 16-character password using all character types (94 chars):
Possible combinations:
9416 = 6.1 × 1031Entropy:
log₂(9416) = 105.4 bitsResult: Excellent Security!
🔬Try Our Interactive Entropy Calculator
See how different password choices affect entropy and security in real-time.
Launch CalculatorPassword Best Practices
Use Unique Passwords
Never reuse passwords across accounts. If one account is compromised, all accounts using the same password are at risk.
Use a Password Manager
Password managers securely store your passwords and generate strong unique passwords for every account.
Enable Two-Factor Authentication
2FA adds an extra security layer beyond just your password, protecting your accounts even if your password is compromised.
Avoid Personal Information
Don't use birthdays, names, addresses, or other easily guessable information in your passwords.
Never Share Passwords
Don't share passwords via email, SMS, or messaging apps. These methods are not secure and can be intercepted.
Change After Breaches
If a service you use suffers a data breach, change your password immediately and check if other accounts are affected.
Common Password Mistakes
Reusing Passwords
Using the same password across multiple accounts. This is the most dangerous mistake you can make.
Using Dictionary Words
Passwords like "password", "welcome", or "admin" can be cracked in seconds using dictionary attacks.
Simple Substitutions
Replacing letters with similar symbols (@→a, 3→e, 0→o) doesn't add much security. Crackers know these patterns.
Sequential Patterns
Patterns like "123456", "abcdef", or "qwerty" are easily guessed and are among the most commonly used passwords.
Short Passwords
Passwords under 12 characters can be cracked relatively quickly, even with good character diversity.
Storing in Plain Text
Writing passwords in notes, spreadsheets, or text files without encryption exposes them to anyone who accesses your device.
How Password Cracking Works
Understanding how attackers crack passwords helps you create better defenses against them.
1. Brute Force Attacks
Trying every possible combination of characters until the correct password is found.
a, b, c ... zzz, aaaa, aaab ...
2. Dictionary Attacks
Testing passwords from lists of common words, phrases, and previously breached passwords.
password, 123456, qwerty ...
3. Rainbow Tables
Pre-computed tables of password hashes that allow instant lookup of passwords from their hashes.
hash → password lookup
4. Credential Stuffing
Using username/password pairs from previous breaches to try on other services (exploiting password reuse).
breach data → other sites
Time to Crack Comparison
| Password Type | Length | Entropy | Time to Crack |
|---|---|---|---|
| All lowercase | 8 chars | 37.6 bits | Instant |
| Upper + lower | 10 chars | 57.0 bits | 2 hours |
| Alphanumeric | 12 chars | 71.5 bits | 5 years |
| All character types | 16 chars | 105.4 bits | 481 trillion years |
* Assuming 1 billion guesses per second (modern GPU capability)
Password Manager Recommendations
A password manager is essential for maintaining unique, strong passwords across all your accounts. Here are our top recommendations:
1Password
Best for families and teams
- ✓Excellent user interface
- ✓Travel Mode for border crossings
- ✓Watchtower security alerts
- ✓Cross-platform support
Starting at $2.99/month
Bitwarden
Best free and open-source
- ✓Fully open-source code
- ✓Generous free tier
- ✓Self-hosting option
- ✓Third-party security audits
Free (Premium: $10/year)
LastPass
Best for beginners
- ✓Simple, intuitive interface
- ✓Password sharing features
- ✓Emergency access
- ✓Multi-device sync
Starting at $3/month
Why Use a Password Manager?
- →You only need to remember one master password
- →Automatically generates strong, unique passwords for every account
- →Securely stores passwords with military-grade encryption
- →Syncs across all your devices
- →Alerts you to compromised passwords and security breaches
Ready to Generate a Strong Password?
Use our free password generator to create cryptographically secure passwords that follow all these best practices.