Не работает шифрование по ГОСТ 28147-89, ГОСТ Р 34.10-2001,ГОСТ Р 34.11-94 (ASP.NET)

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO
Imports CryptoPro.Sharpei
Namespace NameSpace1
    Public Class WebForm1
        Inherits System.Web.UI.Page
        Protected Sub btnEncrypt_Click(ByVal sender As Object, ByVal txt As Object, ByVal lblResult As Object, ByVal ByVale As System.EventArgs)
            Dim gost As Gost28147CryptoServiceProvider
            Dim gost_Encryptor As ICryptoTransform = gost.CreateEncryptor
            Dim fs As New FileStream(Server.MapPath("temp.dat"), FileMode.Create)
            Dim gostCryptoStream As New CryptoStream(fs, gost_Encryptor, CryptoStreamMode.Write)
            Dim enc As UnicodeEncoding, bytes() As Byte
            bytes = enc.GetBytes(txt.Value)
            gostCryptoStream.Write(bytes, 0, bytes.Length)
            gostCryptoStream.Close()
            fs.Close()
            fs = Nothing
            fs = New FileStream(Server.MapPath("temp.dat"), FileMode.Open)
            Dim sr As New StreamReader(fs)
            lblResult.Text = sr.ReadToEnd
            sr.Close()
            fs.Close()
            File.Delete(Server.MapPath("temp.dat"))
 
        End Sub
    End Class
End Namespace