Motivating Example: Microsoft Product Key
When Windows or Microsoft office are
installed, the user is required to enter a 25-
This code (“key”) must be short.
The computer must be able to quickly
recognize whether or not this is a valid key,
without giving away
any clue as to how to
manufacture additional valid keys.
Otherwise thieves would copy the software
CDs and illegally resell them with new
Future attacks will be faster.
How can one
keep the key short, yet still keep up with the
This requires new methods and
involved in design.