Custom Adler16 implementation -TizzyT

    ' Was looking for a good checksum algorithm which was faster than CRC16 and stumbled upon Adler32
    ' Adler32 unfortunately was 32 bits, so I thought I could throw a 16 bit version together given some info
    ' from the wikipedia page: https://en.wikipedia.org/wiki/Adler-32
    ' NOTE: This is completely my attempt at implementing Adler32 at 16bits, use at your on risk.
    ' On a good note, this implementation doesn't have any collisions (when input is also 16bits)

    ' Fast Version
    Public Shared Function Adler16fast(ByVal Data() As Byte) As UShort
        Dim A As UShort = 1, B As ULong = 0
        For i As Integer = 0 To Data.Length - 1
            A = A Xor Data(i)
            B += A
        Next
        Return (CUShort(B Mod 256) << 8) Or A
    End Function

    ' Original POC Version
    Public Shared Function Adler16(ByVal Data() As Byte) As UShort
        Dim A As UShort = 1, B As UShort = 0
        For Each D As Byte In Data
            A = (A + D) Mod 256
            B = (A + B) Mod 256
        Next
        Return (B << 8) Or A
    End Function