Just set a database password on database where linked tables are.
Re-link tables with new password and user will never be prompted
for database password, because password is saved in front database.

You must protect front base from opening with bypass key.

Here is an example of protecting bypass

_________________________
Create macro named Bypass
Action Runcode
function name SetBypassProperty
run macro
__________________________


Function SetBypassProperty()
    Const DB_Boolean As Long = 1
    ChangeProperty "AllowBypassKey", DB_Boolean, False
End Function

Function ChangeProperty(strPropName As String, varPropType As Variant,
varPropValue As Variant) As Integer
    Dim dbs As Object, prp As Variant
    Const conPropNotFoundError = 3270

    Set dbs = CurrentDb
    On Error GoTo Change_Err
    dbs.Properties(strPropName) = varPropValue
    ChangeProperty = True

Change_Bye:
    Exit Function

Change_Err:
    If Err = conPropNotFoundError Then    ' Property not found.
        Set prp = dbs.CreateProperty(strPropName, _
            varPropType, varPropValue)
        dbs.Properties.Append prp
        Resume Next
    Else
        ' Unknown error.
        ChangeProperty = False
        Resume Change_Bye
    End If
End Function

That's all