It seems that HDCP, the high def content protection scheme that's all the rage among
Hollywood types, may not be as secure as the suits had hoped: Princeton University computer science professor Ed Felten
takes a look at the standard's supposedly well-known security flaws and dumbs down the basic tech on his blog so all us
non-math majors can understand. Basically, HDCP relies on a handshake between connected hardware wherein the two
devices send each other a set of rules to be applied to the forty-or-so numbers that constitute both devices'
"secret vector" -- if each device reports the same numerical result (as the pre-determined mathematical rules
dictate they should), sweet high definition content can begin to flow freely. According to Felt, all it takes to figure
out a given device's secret vector or create a workable "phantom" vector is to perform a number of handshakes
equal to the number of elements in the secret vector, followed by a little bit of algebra to tease out the results from
a matrix of equations (follow the "Read" link for a better explanation). Although HDCP-restricted HDMI and
DVI connections aren't prevalent enough yet for anyone to have actually undertaken this project (either that, or fear
of legal reprisals has kept any successful cracks from being published), the simple fact that it's doable could mean
nightmares for Tinseltown sooner rather than later.
[Via Boing Boing]