Here i offer two Funtions in VB.NET to encrypt and decrypt text.

Tested with VB2019 by Thiemo Raoul Melhorn (Germany disabled friend but a good drummer) ready to use by ·geri3d· 100% proof!

    Public Function Encrypt(ByVal plainText As String, ByVal passPhrase As String, ByVal saltValue As String, ByVal hashAlgorithm As String, ByVal passwordIterations As Integer, ByVal initVector As String, ByVal keySize As Integer) As String

        Dim initVectorBytes As Byte()
        initVectorBytes = Encoding.ASCII.GetBytes(initVector)

        Dim saltValueBytes As Byte()
        saltValueBytes = Encoding.ASCII.GetBytes(saltValue)

        Dim plainTextBytes As Byte()
        plainTextBytes = Encoding.UTF8.GetBytes(plainText)

        Dim password As Rfc2898DeriveBytes = New Rfc2898DeriveBytes(passPhrase, saltValueBytes, passwordIterations)
        Dim keyBytes As Byte()
        keyBytes = password.GetBytes(CInt(keySize / 8))

        Dim symmetricKey As RijndaelManaged
        symmetricKey = New RijndaelManaged()
        symmetricKey.Mode = CipherMode.CBC

        Dim encryptor As ICryptoTransform
        encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes)

        Dim memoryStream As MemoryStream
        memoryStream = New MemoryStream()

        Dim cryptoStream As CryptoStream
        cryptoStream = New CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write)
        cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length)
        cryptoStream.FlushFinalBlock()

        Dim cipherTextBytes As Byte()
        cipherTextBytes = memoryStream.ToArray()
        memoryStream.Close()
        cryptoStream.Close()

        Dim cipherText As String
        cipherText = Convert.ToBase64String(cipherTextBytes)
        Encrypt = cipherText

    End Function

    Public Function Decrypt(ByVal cipherText As String, ByVal passPhrase As String, ByVal saltValue As String, ByVal hashAlgorithm As String, ByVal passwordIterations As Integer, ByVal initVector As String, ByVal keySize As Integer) As String

        On Error Resume Next

        Dim initVectorBytes As Byte()
        initVectorBytes = Encoding.ASCII.GetBytes(initVector)

        Dim saltValueBytes As Byte()
        saltValueBytes = Encoding.ASCII.GetBytes(saltValue)

        Dim cipherTextBytes As Byte()
        cipherTextBytes = Convert.FromBase64String(cipherText)

        Dim password As Rfc2898DeriveBytes = New Rfc2898DeriveBytes(passPhrase, saltValueBytes, passwordIterations)
        Dim keyBytes As Byte()
        keyBytes = password.GetBytes(CInt(keySize / 8))

        Dim symmetricKey As RijndaelManaged
        symmetricKey = New RijndaelManaged()
        symmetricKey.Mode = CipherMode.CBC

        Dim decryptor As ICryptoTransform
        decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes)

        Dim memoryStream As MemoryStream
        memoryStream = New MemoryStream(cipherTextBytes)

        Dim cryptoStream As CryptoStream
        cryptoStream = New CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read)

        Dim plainTextBytes As Byte()
        ReDim plainTextBytes(cipherTextBytes.Length)

        Dim decryptedByteCount As Integer
        decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length)

        memoryStream.Close()
        cryptoStream.Close()

        Dim plainText As String
        plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount)

        Decrypt = plainText
    End Function

Usage:

Dim plainText as String = "Secret"
Dim cifferText as String = ""

cifferText = Encrypt(plainText, "dj3md!kwndüs", "s@1tValue", "SHA2", 2, "@1B2c3D4e3F6g7H8", 256))
MsgBox(Encrypt(cifferText, "dj3md!kwndüs", "s@1tValue", "SHA2", 2, "@1B2c3D4e3F6g7H8", 256)))