Commonly Confused Letters for Numbers

A few .Net (VB) functions I recently created to use in a project.

The following is a simple random number generator with a few sub functions broken out to generate a random number and random true or false. I created a utility class which I will continue to build to meet new projects and from previous functions.

The following are what I consider the most commonly confused letters for numbers.

B = 8 (eight)
I = 1 (one)
L = 1 (one)
O = 0 (zero
S = 5 (five)
Z = 2 (two)

So basically the purpose of knowing this is to remove those letters and numbers from a username or password generator.

I googled for more information on this topic and couldn't find anything and I don't consider what I have as definitive, it's just what I could figure out.

I'm sure there is a better (more efficient) way to do most if not all of the functions below. If you have a suggestion feel free to post it in the comments.

Public Class Utility
    Public Shared Function SanitizeSQL(ByVal Input As String) As String
        'Strip Quotes
        Input = Input.Replace("'", "''")
        'Remove Harmful Chars
        Input = Input.Replace("SELECT", "").Replace("drop", "").Replace(";", "").Replace("--", "").Replace("insert", "").Replace("delete", "").Replace("xp_", "").Replace("|", "")
        Return Input
    End Function
    Public Shared Function MySQL_Date_Now() As String
        Return Format(Date.Now, "yyyy-MM-dd hh:mm:ss tt")
    End Function
    Public Shared Function MySQL_Date_Convert(ByVal Input As String) As DateTime
        Return Format(Date.Parse(Input), "yyyy-MM-dd hh:mm:ss tt")
    End Function
    Public Enum PasswordType As Integer
        LowerLettersOnly = 1
        UpperLettersOnly = 2
        NumbersOnly = 3
        NumbersAndLowerLetters = 4
        NumbersAndUpperLetters = 5
        NumbersAndMixedCaseLetters = 6
    End Enum
    Public Shared Function Random_Password( _
         Optional ByVal Length As Integer = 8 _
        , Optional ByVal Type As PasswordType = 1 _
        , Optional ByVal AddChars As String = "" _
        , Optional ByVal RemoveChars As String = "" _
        ) As String
        Dim Numbers_Bag = "34679" 'change to include more numbers
        Dim Letters_Bag = "acdefghjkmnpqrtuwvxy" 'change to include more letters
        Dim CharBag As String = ""
        If Type >= PasswordType.NumbersOnly Then
            CharBag = Numbers_Bag
        End If
        If Type <> PasswordType.NumbersOnly Then
            CharBag += Letters_Bag
        End If
        CharBag += AddChars
        For counter As Integer = 0 To RemoveChars.Length - 1
            If CharBag.IndexOf(RemoveChars.Substring(counter, 1)) >= 0 Then
                CharBag = CharBag.Remove(CharBag.IndexOf(RemoveChars.Substring(counter, 1)), 1)
            End If
        Next counter
        'Begin Creating Random Password
        Dim temp_string As New System.Text.StringBuilder
        For t As Byte = 1 To Length
            Dim random_char As Integer
            random_char = Rnd() * (Len(CharBag) - 1)
            If Type = PasswordType.NumbersAndMixedCaseLetters And Random_True() = True Then
            End If
        Select Case Type
            Case PasswordType.NumbersAndUpperLetters, PasswordType.UpperLettersOnly
                Return temp_string.ToString.ToUpper
            Case Else
                Return temp_string.ToString
        End Select
    End Function
    Public Shared Function Random_True() As Boolean
        Return Random_Number(0, 1)
    End Function
    Public Shared Function Random_Number( _
          Optional ByVal LowerLimit As Integer = 0 _
        , Optional ByVal UpperLimit As Integer = 100000 _
        ) As Integer
        Return CInt(Int(((UpperLimit - LowerLimit + 1) * Rnd()) + Int(LowerLimit)))
        'from MSDN Help - randomvalue = CInt(Int((upperbound - lowerbound + 1) * Rnd() + lowerbound))
    End Function
End Class

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