simple-password-generator

Cryptographically secure password generator for human-readable application passwords.

Overview

A lightweight Java password generator that creates secure, memorable passwords in hyphen-separated format. Perfect for application-specific passwords in OAuth 2.0 environments, IMAP/SMTP authentication, or any scenario requiring user-friendly credentials.

Example outputs: abcd-efgh-ijkl, abc-def-ghi-jklm, qwerty-asdf-zxcv

Features

• Point and shoot: No parameters, no mistakes, no weak passwords
• Cryptographically secure: Uses Java's SecureRandom for true randomness
• Human-readable: Hyphen-separated lowercase letters (easy to type and communicate)
• Strong security: 68-90 bits of entropy, exceeding NIST recommendations (64+ bits)
• No predictable patterns: Truly random character selection
• Uniform distribution: All characters equally likely
• Consistent length: 15-20 total characters including hyphens
• Generation time: sub-millisecond per password

Technical Specifications

Property	Value
Character set	Lowercase a-z (26 chars)
Groups	3 or 4 (random)
Characters per group	3-4 (4 groups) or 4-6 (3 groups) (random)
Total length	15-20 characters (including hyphens)
Character count	13-18 letters (random)
Entropy	68-90 bits

Security

• Minimum entropy: 68 bits (13 characters)
• Maximum entropy: 90 bits (18 characters)
• Brute force resistance: ~9.4 million years at 1 billion attempts/second (minimum case)
• Quantum-resistant: 45 bits effective security against Grover's algorithm

The hyphen-separated format sacrifices ~10 bits of potential entropy for significant usability benefits while maintaining excellent security for application passwords.

Use Cases

• Application-specific passwords for OAuth 2.0 environments
• IMAP/SMTP, Wi-Fi, VPN authentication credentials
• API access tokens in human-readable format
• Temporary access codes/passwords
• Server/app generated passwords

Usage

In a Project

Add the JAR to your classpath (e.g., ~/java-x86_64_sdk/jre/lib/ext/):

import PasswordGenerator;

...
String password = PasswordGenerator.generatePassword();
System.out.println(password); // abc-defg-hijk-lmn
...

Standalone

Download the latest simple-password-generator.jar from Releases.

Command Line

# Generate a single password (using -jar)
java -jar simple-password-generator.jar

# Generate 5 passwords
java -jar simple-password-generator.jar 5

# Alternative: using -cp
java -cp simple-password-generator.jar PasswordGenerator 5

Example Output

[user@MacBook ~]% java -jar simple-password-generator.jar 3
cfso-jiu-qui-bvgc
vlb-sks-zyac-ljw
bsged-yabjf-ofxkpp

Building from Source

# Clone the repository
git clone https://github.com/dutty5/simple-password-generator.git
cd simple-password-generator

# Build manually
javac PasswordGenerator.java
jar cfe simple-password-generator.jar PasswordGenerator PasswordGenerator.class

# Test
java -jar simple-password-generator.jar

License

MIT License - see LICENSE file for details