Committer password policy

This page outlines the policy on committer passwords for LDAP accounts, and explains a bit about the logic behind it.

Minimum password length: eight characters

All passwords must have eight or more characters. You can use any combination of letters, numbers, special characters, and spaces, and there is no upper limit to the password length.

Minimum password entropy size: 54 bits

Entropy size is a measure of how many attempts if would potentially take to crack the password, whether through brute-forcing, dictionary attacks or simply guessing. It is measured in bits that correspond to the size of the maximum number of attempts required in binary format. Thus, a password with an entropy size of 24 bits would require up to 2^24 == 16,777,216 attempts to crack. Entropy size is calculated as the length of the password (in characters/bytes), multiplied by the binary logarithmic (log2) of the alphabetical cardinality of the password, meaning the number of unique characters in the password.

In the example password I am Groot, there are 10 characters in the string, and 8 unique characters in total (`I,a,m,G,r,o,t, and a whitespace), thus the entropy size is:

entropy=10*\log{2}(8) => entropy=10 * 3 => entropy=30

At the ASF, we require a minimum entropy size of 54 bits, meaning it should require more than approximately 18 quadrillion attempts to brute-force a password.

Minimum password complexity: 0.60

We also require a complexity degree of 0.60. Password complexity ranges from 0 to 1, where 0 is a password consisting of only the same letters over and over, and 1 means a password is long enough and with enough entropy to require quadrillions of computations to crack, and also has enough sequential variety to negate any speed improvements a malicious actor might employ in order to simplify or otherwise optimize an attempt at cracking a password.

The exact formula we use is as follows:


Our self-serve page for (re)setting passwords can provide you with an instant assessment of your password strength using these requirements, to help you find a password that is sufficiently strong.

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