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 Public Function Cryptage(ByVal donnees As String) As String

        Dim sha1 As New SHA1Managed
        Convert.ToBase64String(sha1.ComputeHash(Encoding.ASCII.GetBytes(donnees)))
        Dim donneeCryptees() As Byte = ASCIIEncoding.ASCII.GetBytes(donnees)
        Dim cryptageEnString As String = Convert.ToBase64String(donneeCryptees)
        Return cryptageEnString

    End Function
    Public Function Decryptage(ByVal Data As String) As String

        Dim donneeDecryptees() As Byte = Convert.FromBase64String(Data)
        Dim decryptageEnString As String = ASCIIEncoding.ASCII.GetString(donneeDecryptees)
        Return decryptageEnString

    End Function