White Box AES Using Intel's New AES Instructions
Shay Gueron · 2013
White box cryptography deals with content protection scenarios where software decrypts some contents, using a secret key (embedded in the code in some obfuscated way), while the adversary has access to the code and its execution. Obviously, performance is slowed down by the obfuscation overheads. This paper demonstrates a method for using Intel's New AES Instructions to write decryption code without directly using the cipher key or any of the round keys in a register (or in memory). Such implementation can enjoy some of the performance benefits that the AES instructions offer. We show an example where it is more than 2.5 times faster than a lookup table based alternative.