How were the best AES whiteboxes in the CHES 2017 CTF challenge built and broken?
Junwei Wang gave a talk on how the winning entry (#777 by cryptolux) was designed and how team cryptoexperts broke it. Slides, video.

The overvew of the design (slide 9) is:


Multi-layer protection


Inner: encoded Boolean circuit with error detection
Middle: bitslicing
Outer:   virtualization, randomly naming, duplications, dummy
operations

Code size: ~28 MB
Code lines: ∼2.3k
12 global variables including:


computation state (2.1 MB)
program bytecode (15.3 MB)



And the overview of their approach to reversing it:


Reverse engineering ⇒ a Boolean circuit
Single static assignment (SSA) transformation
Circuit minimization
Data dependency analysis
Key recovery with algebraic analysis