These two function provide a simple method to encrypt and decrypt a string. Simply drop this code in to a module, and it is ready for use.
Option Explicit
Public Function Encrypt(ByVal icText As String) As String
Dim icLen As Integer
Dim icNewText As String
icChar = ""
icLen = Len(icText)
For i = 1 To icLen
icChar = Mid(icText, i, 1)
Select Case Asc(icChar)
Case 65 To 90
icChar = Chr(Asc(icChar) + 127)
Case 97 To 122
icChar = Chr(Asc(icChar) + 121)
Case 48 To 57
icChar = Chr(Asc(icChar) + 196)
Case 32
icChar = Chr(32)
End Select
icNewText = icNewText + icChar
Next
Encrypt = icNewText
End Function
Public Function Decrypt(ByVal icText As String) As String
Dim icLen As Integer
Dim icNewText As String
icChar = ""
icLen = Len(icText)
For i = 1 To icLen
icChar = Mid(icText, i, 1)
Select Case Asc(icChar)
Case 192 To 217
icChar = Chr(Asc(icChar) - 127)
Case 218 To 243
icChar = Chr(Asc(icChar) - 121)
Case 244 To 253
icChar = Chr(Asc(icChar) - 196)
Case 32
icChar = Chr(32)
End Select
icNewText = icNewText + icChar
Next
Decrypt = icNewText
End Function