Private/Get-StringEntropy.ps1
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function Get-StringEntropy { Param ( [Parameter(Position=0,Mandatory=$true,ValueFromPipeline=$true)][ValidateNotNullOrEmpty()][string]$Val ) $Bytes = [System.Text.Encoding]::UTF8.GetBytes($Val) $FrequencyTable = @{} foreach ($Byte in $Bytes) { $FrequencyTable[$Byte]++ } $Entropy = 0.0 foreach ($Byte in 0..255) { $ByteProbability = ([Double]$FrequencyTable[[Byte]$Byte])/$Bytes.Length if ($ByteProbability -gt 0) { $Entropy += -$ByteProbability * [Math]::Log($ByteProbability, 2) } } return $Entropy } |