🔐 PassForge

A cryptographically secure password & passphrase generator with a built-in strength meter.

PassForge uses Python's secrets module (a CSPRNG) to forge strong credentials, then tells you exactly how strong they are — entropy in bits, a strength rating, and an estimated brute-force time.

  PassForge · cryptographically secure

  k?=9U[l;N;WOwg]S
  ███████████████████░░░░░  Strong
  entropy: 103 bits · est. crack time: 1.4e+07 millennia

✨ Features

• CSPRNG-backed — uses secrets, not random
• Guaranteed character mix — at least one of each enabled set, then shuffled
• Memorable passphrases — diceware-style word combinations (--passphrase)
• Strength analysis — entropy, rating, and offline crack-time estimate
• Strength checker — rate an existing password with --check
• Flexible — control length, count, and which character classes to include
• Ambiguity filter — drop look-alike characters (Il1O0o) with --no-ambiguous
• Zero dependencies — pure Python standard library, works on 3.7+

🚀 Usage

# One strong 16-char password (default)
python3 passforge.py

# Five 24-char passwords
python3 passforge.py -l 24 -n 5

# Letters + digits only (no symbols)
python3 passforge.py --no-symbols

# A memorable 5-word passphrase
python3 passforge.py --passphrase -w 5

# Rate an existing password
python3 passforge.py --check "hunter2"

Options

Flag	Description
-l, --length	Password length (default 16)
-n, --count	How many to generate
--no-upper / --no-digits / --no-symbols	Drop a character class
--no-ambiguous	Exclude look-alike characters
--passphrase	Generate word-based passphrases
-w, --words	Words per passphrase (default 4)
-s, --separator	Passphrase separator (default -)
--check PASSWORD	Rate the strength of an existing password

📐 How entropy is estimated

For random passwords: entropy = length × log₂(pool_size). For passphrases: entropy = words × log₂(vocabulary). Crack time assumes an aggressive offline attacker at ~10¹⁰ guesses/second and reports expected (half-keyspace) effort. These are conservative estimates to help you reason about strength, not guarantees.

License

MIT