I am making a prediction. For reasons discussed in this previous post, its important that I announce the prediction but keep it a secret until the uncertainty is resolved. Following the suggestion of a commenter, I wrote my prediction in a text file and ran it through the SHA1 secure hash algorithm (using the web tool here.) Here is the hash:
a35fc654c7a68404bcb94b3b6a1d162223ff69e5
Briefly, this is a digital signature that is (for practical purposes) uniquely associated with the text. But the algorithm is “one-way:” unless you have a powerful computer you will not be able to invert the mapping and discover my prediction from the hash.
When the uncertainty is resolved (it will happen in the not-too-distant future) I will post the prediction here. You can then take it and generate the SHA1 hash and verify that it is the one above. That will prove that the prediction I show you is in fact the one that I have made today.
While we are waiting to find out, you can try to predict what my prediction is. (No, my prediction is not about what you will predict I predicted.)
Update on Jan 10 (one day later:) Having forgotten one important detail, I have updated the prediction and the new hash is:
f502acfb48395d6ab223ca30803f98b9bd6fd6ce
When I reveal the prediction, sometime before the Summer Solstice, I will reveal both text files and you will see the (innocuous) reason for the update.
As suggested in the comments, since I am able to modify the text of this blogpost, I should post the hash somewhere that it cannot be modified. Since Twitter puts a timestamp on every tweet and tweets cannot be edited ex post, I tweeted the two hashes. Here and here.
10 comments
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January 10, 2011 at 12:44 am
Evan
Perhaps you should also post a stop date for your prediction? Otherwise, if the prediction is wrong, you could simply claim that it has not been resolved yet. Some stop dates might give clues as to what the prediction is about (i.e. if it stops on Super Tuesday), but you could always choose a random date after the actual stop date to throw people off the scent.
(I’m not bringing your integrity into question here Jeff, but simply trying to improve the mechanism)
January 10, 2011 at 11:46 pm
jeff
good point. The uncertainty will be resolved before the Summer Solstice 2011 and so I will reveal my prediction some day before then.
January 10, 2011 at 8:38 am
Brendan Nyhan
For maximum credibility, you should post the hash elsewhere in a place where you can’t edit it with a timestamp. The problem is that blog posts can be edited and people might not notice a subtle change in the hash.
January 10, 2011 at 11:45 pm
jeff
good idea. i will look around.
January 10, 2011 at 10:37 am
sha1 hash
You win the prize for most interesting use of sha today….
January 10, 2011 at 2:24 pm
Heng
BCS championship game?
January 10, 2011 at 2:26 pm
Heng
Or: e0c15faaaa789b0f5ab1fed1034eef75c48d023b. 🙂
January 10, 2011 at 6:10 pm
Lones Smith
Encryption aside, this won’t lead me to disbelieve in the prophet inequalities….
Click to access ieq.pdf
January 14, 2011 at 10:46 pm
Chris Angell
A prediction about unemployment, housing, or the federal funds rate.
March 28, 2011 at 1:10 am
My Prediction « Cheap Talk
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