Visual Basic.NET - Correccion a los algoritmos de encriptacion y desencriptacion

'--------------------------------------------------------------------------------
'---procedimiento para Encriptar clave
'--------------------------------------------------------------------------------
Public Function Encriptar(ByVal Input As String) As String

Dim IV() As Byte = ASCIIEncoding.ASCII.GetBytes("qualityi") 'La clave debe ser de 8 caracteres
Dim EncryptionKey() As Byte = Convert.FromBase64String("rpaSPvIvVLlrcmtzPU9/c67Gkj7yL1S5") 'No se puede alterar la cantidad de caracteres pero si la clave
Dim buffer() As Byte = Encoding.UTF8.GetBytes(Input)
Dim des As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider
des.Key = EncryptionKey
des.IV = IV

Return Convert.ToBase64String(des.CreateEncryptor().TransformFinalBlock(buffer, 0, buffer.Length()))

End Function

'--------------------------------------------------------------------------------
'---procedimiento para Desencriptar clave
'--------------------------------------------------------------------------------
Public Function Desencriptar(ByVal Input As String) As String

Dim IV() As Byte = ASCIIEncoding.ASCII.GetBytes("qualityi") 'La clave debe ser de 8 caracteres
Dim EncryptionKey() As Byte = Convert.FromBase64String("rpaSPvIvVLlrcmtzPU9/c67Gkj7yL1S5") 'No se puede alterar la cantidad de caracteres pero si la clave
Dim buffer() As Byte = Convert.FromBase64String(Input)
Dim des As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider
des.Key = EncryptionKey
des.IV = IV
Return Encoding.UTF8.GetString(des.CreateDecryptor().TransformFinalBlock(buffer, 0, buffer.Length()))

End Function