EFF Diceware Passphrase Generator (Shannon Entropy & Crack Time)

CSPRNG Diceware Passphrase
70.4 bitsStrong
Generating...
Brute-Force Offline Estimate: Thousands of centuries (Very Strong)
Generator Parameters
~64.6 word entropy bits
3 words45 (Recommended)678 words
Security Presets
Instant Alternative Passphrases
5
Words
0
Characters
70.4
Entropy Bits
Technical Reference & Architecture Guide

EFF Diceware Passphrase Technical Reference & Entropy Guide — Reference Guide

Comprehensive specification for generating high-entropy multi-word passphrases using Diceware wordlists, custom delimiters, and brute-force resistance models.

Key Parameters & Controls

wordCountInteger (Range: 3 - 10)

Total number of random words selected from the EFF long wordlist (7,776 words, 12.92 bits per word).

separatorString (hyphen, dot, underscore, space, custom)

Delimiter string placed between generated words to preserve readability and parsing structure.

capitalizeBoolean

Applies Title Case to each word, adding additional entropy against lower-case dictionary attacks.

includeNumberBoolean

Appends a cryptographically random digit (0-999) to satisfy legacy enterprise password complexity rules.

Pro Tips & Best Practices

Common Gotchas & Troubleshooting

Browser warns about low entropy or repeats

Increase word count to at least 5 words and verify window.crypto is accessible in secure HTTPS contexts.

Website rejects passphrase due to length restrictions

Use 4 longer words or substitute long delimiters with hyphens to stay under restrictive 32 or 64-character legacy input limits.

Frequently Asked Questions

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