Felix is a pencil-and-paper cipher offering relatively good security for causal use. Unlike modern encoding schemes that require, at a minimum, a computer to be of any practical consequence; Felix requires only that you follow three elementary rules (outlined below). If you're curious about cryptology, the Felix cipher is a great place to start. This cipher can typically be understood and applied, even by children, in a handful of minutes. Quite simply that means, its easy to implement for common folks