© The Author(s), under exclusive license to APress Media, LLC, part of Springer Nature 2024
D. Johnston, R. FantDesigning to FIPS-140https://doi.org/10.1007/979-8-8688-0125-9_8

8. Entropy Assessment

David Johnston1   and Richard Fant2
Hillsboro, OR, USA
Austin, TX, USA

8.1 What Is Entropy?

Entropy is commonly referred to as a measure of disorder or information capacity of a communication channel. Entropy as defined by Alfréd Rényi is called Rényi Entropy with a parameter alpha. There are an infinite number of entropy measures based on that value that can take on any nonnegative real value. The equation is
$$ {H}_{\alpha }(X)={H}_{\alpha}\left({p}_1,\dots, {p}_n\right)=\frac{1}{1-\alpha}\;{\log}_2\left(\sum \limits_{i=1}^n{P}_i^{\alpha}\right),\alpha \ge 0,\alpha \ne 1 $$

H is the symbol for entropy. X is the symbol ...

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