Generalising the array split obfuscation

An obfuscation is a behaviour-preserving program transformation whose aim is to make a program “harder to understand”. Obfuscations are mainly applied to make reverse engineering of object-oriented programs more difficult. In this paper, we propose a fresh approach by obfuscating abstract data-types allowing us to develop structuredependent obfuscations that would otherwise (traditionally) not be available. We regard obfuscation as data refinement enabling us to produce equations for proving correctness and we model the data-type operations as functional programs making our proofs easy to construct. We show how we can generalise an imperative obfuscation — an array split — so that we can apply it to more general data-types and we give specific examples for lists and matrices. We develop a theorem which allows us, under certain conditions, to produce obfuscated operations directly. Our approach allows us to produce random obfuscations and we give an example for our list data-type.