  The classical combinatorics-based password strength formula provides a result
in tens of bits, whereas the NIST Entropy Estimation Suite give a result
between 0 and 1 for Min-entropy. In this work, we present a newly developed
metric -- Expectation entropy that can be applied to estimate the strength of
any random or random-like password. Expectation entropy provides the strength
of a password on the same scale as an entropy estimation tool. Having an
'Expectation entropy' of a certain value, for example, 0.4 means that an
attacker has to exhaustively search at least 40\% of the total number of
guesses to find the password.
