Diceware

The level of unpredictability of a Diceware passphrase can be easily calculated: each word adds 12.9 bits of entropy to the passphrase (that is, bits). Originally, in 1995, Diceware creator Arnold Reinhold considered five words (64.6 bits) the minimal len

This article is a bit dated, but the entropy (randomness) with Diceware passwords is substantial and can present a challenge to the NSA. FAQ: Is the source available?

This does not necessarily give better entropy (but protects against entropy loss due to non prefix code, see Security Traps below), and it might improve phrase readability.

The total entropy of a password with words is bits; The total number of combinations with this number of words is (the dictionary contains words); Time to crack using brute force, investigating 50% of the total combinations Assuming 1,000,000,000,000,000

The level of unpredictability of a Diceware passphrase can be easily calculated: each word adds 12.9 bits of entropy to the passphrase (that is, bits). Originally, in 1995, Diceware creator Arnold Reinhold considered five words the minimal length needed b

A Diceware passphrase generator, implemented in JavaScript, that uses the Cryptographically Secure Pseudo Random Number Generator (CSPRNG) in your browser as its source of entropy instead of rolling physical dice.

The entropy offered by Diceware is 12.9 bits per word (log2 (7776)), so you can compute the entropy of a Diceware password given its word length, for example, a five-word passphrase has an entropy of 64.5 bits.