function Get-Hash([string]$textToHash) {
    $hasher = new-object System.Security.Cryptography.MD5CryptoServiceProvider
    $toHash = [System.Text.Encoding]::UTF8.GetBytes($textToHash)
    $hashByteArray = $hasher.ComputeHash($toHash)

    foreach($byte in $hashByteArray){
        $result += "{0:X2}" -f $byte
    }

    return $result;
}

$ClearClipboard = $true
$PreviousHash = Get-Hash(Get-Clipboard)

while ($true) {
    $Clipboard = Get-Clipboard
    $ClipboardHash = Get-Hash($Clipboard)

    if ($ClipboardHash -eq $PreviousHash) {
        Write-Host "NOCHG"
        Start-Sleep -Milliseconds 250
        Continue
    }
    elseif ($Clipboard -match '^bankid:\/\/\/') {
        Write-Host $Clipboard
        start "$Clipboard"
    }
    else {
        Write-Host "CHG"
    }

    if ($ClearClipboard) {
        Set-Clipboard -Value $null
    }

    $PreviousHash = Get-Hash($Clipboard)
    Start-Sleep -Milliseconds 250
}