This is the story of the HDCP master key. How in 2010 we derived it from various public sources and from a bunch of cheapish hardware (and how we made money in the process!), and then published it on pastebin. After that it was just wait-and-see what Intel and the rest of the world would do.
With the master key anyone can make source and sink keys that interoperate with any HDCP device.
Oh, and how I learnt how to spell "forty".
HDCP MASTER KEY (MIRROR THIS TEXT!)
This is a forty times forty element matrix of fifty-six bit hexadecimal numbers.
To generate a source key, take a forty-bit number that (in binary) consists of twenty ones and twenty zeroes; this is the source KSV. Add together those twenty rows of the matrix that correspond to the ones in the KSV (with the lowest bit in the KSV corresponding to the first row), taking all elements modulo two to the power of fifty-six; this is the source private key.
To generate a sink key, do the same, but with the transposed matrix.
6692d179032205 b4116a96425a7f ecc2ef51af1740 959d3b6d07bce4 fa9f2af29814d9 82592e77a204a8 146a6970e3c4a1 f43a81dc36eff7 568b44f60c79f5 bb606d7fe87dd6 1b91b9b73c68f9 f31c6aeef81de6 9a9cc14469a037 a480bc978970a6 997f729d0a1a39 b3b9accda43860 f9d45a5bf64a1d 180a1013ba5023 42b73df2d33112 851f2c4d21b05e 2901308bbd685c 9fde452d3328f5 4cc518f97414a8 8fca1f7e2a0a14 dc8bdbb12e2378 672f11cedf36c5 f45a2a00da1c1d 5a3e82c124129a 084a707eadd972 cb45c81b64808d 07ebd2779e3e71 9663e2beeee6e5 25078568d83de8 28027d5c0c4e65 ec3f0fc32c7e63 1d6b501ae0f003 f5a8fcecb28092 854349337aa99e 9c669367e08bf1 d9c23474e09f70