Private Function CaesarCypher(ByVal value As String, ByVal shift As Integer) As String
Dim buffer As Char() = value.ToCharArray()
For i As Integer = 0 To buffer.Length - 1
Dim letter As Char = buffer(i)
If Char.IsLetter(letter) Then
Dim isLower As Boolean = Char.IsLower(letter)
letter = CChar((letter + shift))
letter = CChar((letter - 26))
ElseIf letter < "a"c Then
letter = CChar((letter + 26))
letter = CChar((letter - 26))
ElseIf letter < "A"c Then
letter = CChar((letter + 26))
Return New String(buffer)
Dim secretMessage As String = "STGML MK
Ow sjw s yjgmh gx .FWL vwnwdghwjk ozg sjw kauc sfv lajwv gx klsjlafy Nakmsd Klmvag, ujwslafy s fwo hjgbwul sfv jmffafy al, bmkl lg lwkl kaehdw ugvw gj ljq gml ksehdwk xjge glzwj vwnwdghwjk.
Lzak lggd osk afkhajwv tq zllh://bkxavvdw.fwl, ozauz ak bmkl sowkgew.
Ax qgm sjw aflwjwklwv af ogjcafy gf .FWL Xavvdw hdwskw kwfv qgmj jwkmew sfv dafck lg s ugmhdw gx qgmj twkl xavvdwk lg vglfwlxavvdw sl wflwuzkgdmlagfk vgl uge. Lzw egkl aehjwkkanw xavvdw oadd ywl lzw bgt.
zllh://ooo.wflwuzkgdmlagfk.uge"
Dim notSoSecretMessage As String = CaesarCypher(secretMessage, -18)
Console.WriteLine(notSoSecretMessage)