Participants submit C source code with interface
void AES_128_encrypt(unsigned char ciphertext, unsigned char plaintext);
that performs AES-128 encryption with some key. Other participants attempt to find that key from the submission. A mechanical referee checks if a guess of the key is correct. A rating system awards points (strawberries and bananas) as a function of how much time one's submission remains unbroken, and for breaking a submission. Survival range has been from 1 minute to a record 28 days 13h 42'.
What where the techniques used by the leading participants, both for making whiteboxes, and attacking them? The only clear thing is that there was an inflation in size; the winner is 28MByte.