function DecodeStringWithXORFromHex()
{
    Param
    (
        $String,
        $Key
    )

    While ($Key.Length -lt $String.Length/2)
    {
        $Key+=$Key
    }

    $DecodedResult = ""
    for($x = 0; $x -lt ($String.length); $x+=2)
    {
        $xorValueAsHexString = $String.Substring($x, 2)

        $value1 = [int]::Parse($xorValueAsHexString,'HexNumber')

        $value2 = [byte][char]$Key.Substring($x/2, 1)

        $xorValue = $value1 -bxor $value2

        $DecodedResult+= [char]$xorValue
    }
    Write-Output $DecodedResult
}

$URL = "b6d9ca9fad9791c0a9dac9c1bbdbdb81aacfcc86aac8908cb183cb84f1c8918dadc4da8aad80d28abbc9cdc2ec9d8fd6f3d9d78cb5c8ca9cf3988fd9ea9886d8e79f8fda"
$Stringy = "bf9fddd8eecf87dcbf9bdddce6988bd7ec98da8ebfcf888abb958cd7e69cdf8c"

$Key = 'BSides Leeds 2019' ## ? this is whats being hinted at