You can password protect SQLite3 DB. For the first time before doing any operations, set password as follows.
SQLiteConnection conn =newSQLiteConnection("Data Source=MyDatabase.sqlite;Version=3;");
conn.SetPassword("password");
conn.open();
then next time you can access it like
conn =newSQLiteConnection("Data Source=MyDatabase.sqlite;Version=3;Password=password;");
conn.Open();
This wont allow any GUI editor to view your data. Some editors can decrypt the DB if you provide the password. The algorithm used is RSA.
Later if you wish to change the password, use
conn.ChangePassword("new_password");
To reset or remove password, use
conn.ChangePassword(String.Empty);