You can use this code to encrypt and decrypt a stored values. You can also set you own encryption key that will be stored in a String(EncryptionKey) http://www.pcreview.co.uk/forums/encrypt-my-settings-setting-t2642486.html

Encryption_Decryption.vbs

Imports System.Security.Cryptography
Imports System.Text

Module mod_Globals

Public EncryptionKey As String = "justsomewordstobeusedasacryptionkey"

Public Function EncryptString128Bit(ByVal vstrTextToBeEncrypted As
String, ByVal vstrEncryptionKey As String) As String

Dim bytValue() As Byte
Dim bytKey() As Byte
Dim bytEncoded() As Byte
Dim bytIV() As Byte = {121, 241, 10, 1, 132, 74, 11, 39, 255,
91, 45, 78, 14, 211, 22, 62}
Dim intLength As Integer
Dim intRemaining As Integer
Dim objMemoryStream As New MemoryStream
Dim objCryptoStream As CryptoStream
Dim objRijndaelManaged As RijndaelManaged

vstrTextToBeEncrypted =
StripNullCharacters(vstrTextToBeEncrypted)

bytValue =
Encoding.ASCII.GetBytes(vstrTextToBeEncrypted.ToCharArray)

intLength = Len(vstrEncryptionKey)

If intLength >= 32 Then
vstrEncryptionKey = Strings.Left(vstrEncryptionKey, 32)
Else
intLength = Len(vstrEncryptionKey)
intRemaining = 32 - intLength
vstrEncryptionKey = vstrEncryptionKey &
Strings.StrDup(intRemaining, "X")
End If

bytKey = Encoding.ASCII.GetBytes(vstrEncryptionKey.ToCharArray)

objRijndaelManaged = New RijndaelManaged

Try
objCryptoStream = New CryptoStream(objMemoryStream,
objRijndaelManaged.CreateEncryptor(bytKey, bytIV),
CryptoStreamMode.Write)
objCryptoStream.Write(bytValue, 0, bytValue.Length)
objCryptoStream.FlushFinalBlock()
bytEncoded = objMemoryStream.ToArray
objMemoryStream.Close()
objCryptoStream.Close()
Catch

End Try

Return Convert.ToBase64String(bytEncoded)

End Function

Public Function DecryptString128Bit(ByVal vstrStringToBeDecrypted
As String, ByVal vstrDecryptionKey As String) As String

Dim bytDataToBeDecrypted() As Byte
Dim bytTemp() As Byte
Dim bytIV() As Byte = {121, 241, 10, 1, 132, 74, 11, 39, 255,
91, 45, 78, 14, 211, 22, 62}
Dim objRijndaelManaged As New RijndaelManaged
Dim objMemoryStream As MemoryStream
Dim objCryptoStream As CryptoStream
Dim bytDecryptionKey() As Byte
Dim intLength As Integer
Dim intRemaining As Integer
Dim intCtr As Integer
Dim strReturnString As String = String.Empty
Dim achrCharacterArray() As Char
Dim intIndex As Integer

bytDataToBeDecrypted =
Convert.FromBase64String(vstrStringToBeDecrypted)

intLength = Len(vstrDecryptionKey)

If intLength >= 32 Then
vstrDecryptionKey = Strings.Left(vstrDecryptionKey, 32)
Else
intLength = Len(vstrDecryptionKey)
intRemaining = 32 - intLength
vstrDecryptionKey = vstrDecryptionKey &
Strings.StrDup(intRemaining, "X")
End If

bytDecryptionKey =
Encoding.ASCII.GetBytes(vstrDecryptionKey.ToCharArray)

ReDim bytTemp(bytDataToBeDecrypted.Length)

objMemoryStream = New MemoryStream(bytDataToBeDecrypted)

Try

objCryptoStream = New CryptoStream(objMemoryStream,
objRijndaelManaged.CreateDecryptor(bytDecryptionKey, bytIV),
CryptoStreamMode.Read)
objCryptoStream.Read(bytTemp, 0, bytTemp.Length)
objCryptoStream.FlushFinalBlock()
objMemoryStream.Close()
objCryptoStream.Close()

Catch

End Try

Return StripNullCharacters(Encoding.ASCII.GetString(bytTemp))

End Function


Public Function StripNullCharacters(ByVal vstrStringWithNulls As
String) As String

Dim intPosition As Integer
Dim strStringWithOutNulls As String

intPosition = 1
strStringWithOutNulls = vstrStringWithNulls

Do While intPosition > 0
intPosition = InStr(intPosition, vstrStringWithNulls, vbNullChar)

If intPosition > 0 Then
strStringWithOutNulls = Left$(strStringWithOutNulls, intPosition - 1) & _
Right$(strStringWithOutNulls,
Len(strStringWithOutNulls) - intPosition)
End If

If intPosition > strStringWithOutNulls.Length Then
Exit Do
End If
Loop

Return strStringWithOutNulls

End Function


End Module


'Then to call this code do the following:

'Get Password
Dim strPassword as string = DecryptString128Bit(My.Settings.Password, EncryptionKey)

'Save Password
My.Settings.Password = EncryptString128Bit(txt_Password1.Text.Trim, EncryptionKey)

'Change file extn to .vbs
Set objExcel = CreateObject("Excel.Application")
objExcel.Application.Run "'D:\Work\W3\Deploy.xlsm'!Deploy"
objExcel.DisplayAlerts = true
objExcel.Application.Quit
Set objExcel = Nothing