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Comment: Re:Activity time! (Score 1) 346

by Rupan (#19169445) Attached to: AACS Revision Cracked A Week Before Release
This comment exhibits a clear lack of understanding. A byte of data is 8 bits and requires *two* "hex digits" when stored in text format. So for each key, you're looking at 32 ascii characters.

Now consider that 16 bytes is 128 bits (16*8). So we're looking at 2^128, or 3.402823669e+38 possible keys. Multiply that by 32, and you'll have the total size of the text file containing all possible AACS keys.

Now consider attempting to brute force the AACS key for _ONE_ AACS-protected title using the above text file as a dictionary. Assuming a gross oversimplification of the AACS protocol -- that it includes _ONLY_ AES encryption, runs _ONLY_ on x86, and uses the fastest FOSS AES implementation (Gladman) -- we're looking at about 13000 instructions for a full implementation.

Assuming a machine rated at 5000 MIPS (essentially a high-end modern desktop PC), we can test about 385,000 keys per second assuming a known-plaintext attack.

You're looking at 899190255900501182414210763 years to find _ONE_ key. Assuming that the universe is 13.7 BYO, we're looking at 65634325248211765 times the age of the universe to find _ONE_ key.

fortune: cannot execute. Out of cookies.