  Mixed Boolean-Arithmetic (MBA) obfuscation is a common technique used to
transform simple expressions into semantically equivalent but more complex
combinations of boolean and arithmetic operators. Its widespread usage in DRM
systems, malware, and software protectors is well documented. In 2021, Liu et
al. proposed a groundbreaking method of simplifying linear MBAs, utilizing a
hidden two-way transformation between 1-bit and n-bit variables. In 2022,
Reichenwallner et al. proposed a similar but more effective method of
simplifying linear MBAs, SiMBA, relying on a similar but more involved theorem.
However, because current linear MBA simplifiers operate in 1-bit space, they
cannot handle expressions which utilize constants inside of their bitwise
operands, e.g. (x&1), (x&1111) + (y&1111). We propose an extension to SiMBA
that enables simplification of this broader class of expressions. It surpasses
peer tools, achieving efficient simplification of a class of MBAs that current
simplifiers struggle with.
