> I must admit that I don't understand how the number of characters corresponds to bits of entropy. Know of a resource that explains this? There are 26 letters

> I must admit that I don't understand how the number of characters corresponds to bits of entropy. Know of a resource that explains this? There are 26 letters; mixed-case doubles that for 52 choices; digits add 10 for a total of 62 possible choices for each character. That means that 2 characters have 62^2 possible configurations, 3 62^3 and so forth. If you take the resulting number and calculate the ceiling of its logarithm in base 2, you get the number of bits needed to represent it: (ceiling (log (expt 62 11) 2)) → 66 -0.5038376