Pronounceable Password Generator

A C++ utility that generates human-readable, memorable passwords while avoiding dictionary words. Creates secure passwords using pronounceable syllables with configurable complexity options.

Features

• Generates pronounceable password bases (alternating consonants/vowels)
• Configurable password length
• Batch generation — produce N passwords in one call (-count)
• Optional 2-digit number injection (-digits)
• Optional uppercase letter injection (-upper)
• Optional special character injection (-special)
• Customizable special character set (-chars)
• Exclude visually ambiguous characters (-no-ambiguous)
• Entropy estimate and strength label (-strength)
• Cryptographically seeded PRNG throughout (no rand()/srand())

Build Instructions

Prerequisites

• C++20 compatible compiler (GCC, Clang, MSVC)
• CMake 3.8+

Building

mkdir build && cd build
cmake ..
cmake --build . --config Release

Or using presets (recommended):

cmake --preset linux-release   # Linux / macOS
cmake --preset windows-release # Windows
cmake --build --preset linux-release

Usage

Basic — 10-character pronounceable password

./passgen -length 10

Example output: zexovakipo

With numbers and special characters

./passgen -length 12 -digits -special

Example output: vupa41@jelowi

With uppercase

./passgen -length 12 -digits -upper -special

Example output: vuPa41@jelowi

Batch generation

./passgen -length 14 -digits -special -count 5

Example output:

zupakire93!bevo
nomifatu!47reba
...

Show entropy estimate

./passgen -length 14 -digits -upper -special -strength

Example output: zupA93!kirebavo [82.4 bits, Strong]

Exclude ambiguous characters

./passgen -length 12 -digits -no-ambiguous

Removes 0, O, l, 1, I from all character sets.

Custom special characters

./passgen -length 14 -special -chars "£€$"

Example output: jaxu£pokiter

Help and version

./passgen -help
./passgen -version

Options

Flag	Value	Description
-length N	Yes	Total password length (required)
-count N	Yes	Number of passwords to generate (default: 1)
-digits	No	Inject 2 random digits
-upper	No	Inject 1 uppercase letter
-special	No	Inject 1 special character
-chars CHARS	Yes	Custom special character set (default: !@#$%^&*)
-no-ambiguous	No	Exclude visually ambiguous chars: 0 O l 1 I
-strength	No	Print entropy estimate and strength label
-version	No	Print version and exit
-help	No	Print this help and exit

Password Generation Strategy

1. Computes base length: total length minus slots reserved for injected groups
2. Builds a pronounceable base using alternating consonants/vowels
3. Generates each injected group (digits, uppercase, special) independently
4. Shuffles insertion order, then splices each group at a random position
5. All randomness from a single mt19937 seeded by std::random_device — no rand()

Entropy estimation

entropy = length × log₂(alphabet_size)

where alphabet size accumulates: 26 lowercase + 26 uppercase (if -upper) + 10 digits (if -digits) + special set size (if -special), minus ambiguous chars (if -no-ambiguous).

Bits	Label
< 40	Weak
40–59	Fair
60–79	Good
≥ 80	Strong

License

MIT License - see LICENSE