Fast Walsh Transform

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Fast Walsh Transform Applet

This applet performs the Walsh transform on its inputs.

This transform is useful for computing the non-linearity of boolean functions with arbitrary numbers of inputs - an attribute of interest to designers of cyphers.

Type in the entries in the logic table of the boolean function on the left - e.g. 1 0 0 1 0 1 1 0. Put spaces, commas or carraige returns between the entries. Then hit the button to perform the transform.

The source code is available here:

The code was based on an algorithm described by Terry Ritter.

Links to Ritter's web pages

[Measuring Boolean Function Nonlinearity by Walsh Transform]
[Walsh-Hadamard Transforms - a literature survey]
[Active Boolean Function Nonlinearity Measurement in JavaScript]

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