What should I be thinking?
Here is the beercoin transaction ID of the transaction where I put the SHA512 hash, as a comment, of what you should be thinking:
7eb2c0a21fbb0fecce11ccb63d39d978a0369c8918b22476afe6836e423e8787
Here's the hash:
923ec4567865733ba5e4b917ce92a745cde5f966dd02a83b39eee713b85d4ffaea7a0a9e7346119
f1b9a250ddeb29814c8f1d084056d5aa40fc2470a1cb69d4d
In a couple of weeks, I'll give the message that the hash corresponds to. I chose to store the hash in the beercoin blockchain because it's the only wallet I have right now that takes comments. Unfortunately, no one has put up a block explorer for beercoin. If you want to verify the transaction ID, you'll have to download the beercoin wallet. Also, in case you doubt the ability of SHA512 to resist birthday attack, you should realize that bitcoin transactions are hashed SHA256.
[addendum]e4ea5224d79c62d337bd7a2e008f7e33b7f5d2f357b6a6d8a9602feb448bd39a
af0bb3e7fa25d8b81204d18234138fca62d5c9355d843e5ec4ccdd1159a555565c2370636bfc941
aefb37e039e057fc2dcdd1ff486ef91b7a536eb8b26404bb8
