🛡️ Pattern Detection

Advanced pattern detection to identify common weak password patterns and apply appropriate penalties.

Live Pattern Detection

Type a password to see real-time pattern detection in action.

Test Password

Pattern Types

1. Sequential Characters (-15%)

Examples: abc, 123, xyz, 321

2. Repeated Characters (-10%)

Examples: aaa, 111, !!!

3. Keyboard Patterns (-20%)

Examples: qwerty, asdf, 12345

4. Common Substitutions (-10%)

Examples: p@ssw0rd, h3ll0

5. Date Patterns (-15%)

Examples: 2024, 01011990

Pattern Examples

Click on any example to test it.

❌ Weak Patterns

⚠️ Medium Patterns

✅ Strong (No Patterns)

Integration with PasswordMeter

Pattern detection is automatically enabled when Config.DetectPatterns = true.

Password with Pattern Detection

Password Requirements:

Configuration

var config = new PasswordMeterConfig
{
    DetectPatterns = true,
    CheckCommonPasswords = true,
    ScoringCurve = ScoringCurveType.Step
};

Technical Details

The pattern detection algorithm performs a single-pass analysis with O(n) complexity:

Sequential: Compares consecutive characters for ascending/descending sequences
Repeated: Looks for 3+ identical consecutive characters
Keyboard: Matches against a predefined list of common keyboard patterns
Substitutions: Counts common leet-speak character replacements
Dates: Uses regex patterns to detect date formats

Performance: Average detection time < 2ms

Penalties are cumulative but capped at 50% maximum reduction:

Pattern Type	Penalty
Sequential Characters	-15%
Repeated Characters	-10%
Keyboard Patterns	-20%
Common Substitutions	-10%
Date Patterns	-15%
Maximum Total	-50%

The penalty is applied as a percentage reduction to the base password score.

using BlazorX.Components.PasswordMeter.Services;

var patternService = new PatternDetectionService();
var result = patternService.DetectPatterns("qwerty123");

if (result.HasAnyPatterns)
{
    Console.WriteLine($"Penalty: {result.PenaltyScore}%");
    
    foreach (var pattern in result.DetectedPatterns)
    {
        Console.WriteLine($"- {pattern}");
    }
}

// Output:
// Penalty: 20%
// - Keyboard pattern detected (e.g., qwerty, asdf)