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cory doctorow
and Brian and Peter around to various smoke-filled rooms to
make sure that Microsoft DRM finds a hospitable home in the
future world. Companies like Microsoft steer like old Buicks, and
this issue has a lot of forward momentum that will be hard to
soak up without driving the engine block back into the driver’s
compartment. At best I think that Microsoft might convert some
of that momentum on DRM into angular momentum, and in so
doing, save all our asses.
Let’s dive into it.
1. DRM systems don’t work
This bit breaks down into two parts:
1. A quick refresher course in crypto theory
2. Applying that to DRM
Cryptography — secret writing — is the practice of keeping secrets.
It involves three parties: a sender, a receiver, and an attacker
(actually, there can be more attackers, senders and recipients, but
let’s keep this simple). We usually call these people Alice, Bob,
and Carol.
Let’s say we’re in the days of Caesar, the Gallic War. You need to
send messages back and forth to your generals, and you’d prefer
that the enemy doesn’t get hold of them. You can rely on the idea
that anyone who intercepts your message is probably illiterate,
but that’s a tough bet to stake your empire on. You can put your
messages into the hands of reliable messengers who’ll chew them
up and swallow them if captured — but that doesn’t help you if
Brad Pitt and his men in skirts skewer him with an arrow before
he knows what’s hit him.
So you encipher your message with something like ROT-13,
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