http://www.youtube.com/watch?v=xIXq-ZIQP7c

I made the service and this video. Just trying to share this with people. If you know anyone who has to prove the time of files for their job or whatever, please share this with them!

If you're curious, a good discussion on the service itself:
http://www.reddit.com/r/Bitcoin/comments/1ssxd4/long_time_lurker_first_time_poster_i_just_made_a/

I'm next looking to change it such that bitcoins are not wasted. It is a nearly negligible amount, but for a long-term service I think its better. I've heard many interesting suggestions, you can let me know if you find any others.

http://cryptostamp.net

There are a few similar website, but I recently made this one to hopefully make a service which is completely free. User sends content, Merkle Tree created once a day and root submitted to block chain, and user can check back the next day to get the required Merkle Tree nodes to verify their content.

Reddit post created some interesting conversations you can checkout: http://www.reddit.com/r/Bitcoin/comments/1ssxd4/long_time_lurker_first_time_poster_i_just_made_a/

Any suggestions or questions are welcome. Please forward a link to this website to anyone you think my find it interesting or useful.

Also, share if you know any important societal need for such a service let me know. What's nice is that this can be done very cheaply, so it could even be applied to every photo someone takes on their phone for instance. I just don't know the use-case for wanting proven timestamps for all your photos (not that one doesn't exist).

cryptostamp.net

Feel free to try it out and let me know if you have questions or suggestions. Also share it with others who may find it interesting or useful.

That could work actually. You cannot directly use the 256 bit hash as a private key (will need to look closer into DSA for that). But, at the very least you can always force a private key generator to use an insecure 256 bit seed then anyone can reproduce this.

How would this reduce transaction fees though? Doesn't it double the transaction fees as you need to pay this address and then have this address pay you back? Is there a way to eliminate transaction fees?

Throwing 0.00000001 BTC at a non-existent account is such little damage to bitcoin since someone would need to use this utility 100 million times paying about 0.0005*100,000,000=50,000 BTC in transaction fees before a single bitcoin is lost. Myself (plus I'm sure some others out there) have already done that damage to bitcoin accidentally as I lost roughly 1 BTC as I lost a wallet.dat file.

In the end, this idea and code is still roughly a week old, so I do like conversations about the best way to accomplish this task.

Also, if anyone (who is not a newbie) wants to link this thread in the following thread, please do so as this is very relevant:
https://bitcointalk.org/index.php?topic=139443.0

I wrote a utility that allows you to timestamp a file by paying 0.00000001 BTC to an address representing the secure hash of the file. It essentially throws that BTC away (you can pay a transaction fee as well) and adds a little overhead in terms of disk (~258 bytes to block-chain) which are slightly harmful to Bitcoin but we can offer a new security service if people want to use this utility. Such a utility could be useful for proving a picture was taken prior to some time or proving you completed homework prior to the due date. At its core, you can prove the existence of data BEFORE a time period. Proving AFTER is like taking a picture of a hostage with the current day's newspaper in their hands (harder to do this purely digitally).

I want people to use this. Let me know if you think this idea could be useful and/or how you may use it. Also, if you have any questions about how it works or why its secure, I can answer those.

Github repository if you would like to see or try the code:
https://github.com/newell-purdue/bitstamper