When reading this number

09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

I thought it was the fingerprint of a GPG key.

The first time I came across it, it was encoded in a puzzle; not a particularly difficult one (what key is inbetween of F8 and F10 on your keyboard?).

Turns out that this number can be used to decrypt most HD-DVDs produced so far.

No, you can’t really think you have a copyright on this number? You could have it as a registered trademark, I guess. But I think everybody will be using it to refer to you. :-)

From a crypto point of view, it was just a matter of time until this number leaked out. And in fact, the HD-DVD encryption was designed to handle this cases (but it wasn’t used correctly). Face it: cryptographers have been telling you right from the beginning that your encryption will be broken by it’s very nature (remember: you are shipping decryption keys worldwide in your HD-DVD player devices).

[Update: others thought it might be an IPv6 address maybe?]

[Update #2: Google thinks there are about 300k pages with this number. Maybe we can stop this meme now? :-)]

[Update #3: it was pointed out to me that nobody claimed to have copyright on this number, but that it is a device to cirumvent encryption and thus violates the DMCA. And that this is similar to distributing magic markers that could be used to ‘crack’ a famous CD protection used by Sony some time ago…]