Notarize a file into the bitcoin blockchain, command-line version.
Trusted digital timestamping can be used to certify that you held a certain information at a certain point in time.
First run btstamp on your file. Btstamp hashes your file into a bitcoin address.
$ ./btstamp poem.txt
12c3xdrDuoHBz8R6zo8kWJXtnTmBNx8cbA
Then transfer a fractional amount of bitcoins to the generated address. This destroys the bitcoins, so just send a minimal amount.
After the transfer was accepted by the bitcoin network, you can use a blockchain viewer to verify the transaction date. Be sure to keep an exact copy of the hashed data or this proof won't be valid.
This software uses btproof's algorithm and code, and is indeed compatible with btproof.
The btstamp script requires btproof's website sources, which you can obtain by importing the 'btproof' submodule.
git submodule init
git submodule update
It also requires coffeescript to be installed.
The "btstamp" script was created by Michele Bini and is available with a MIT-style license. Please consult the LICENSE file for more information.
It links to "btproof" code that is also available with a MIT-style license. (https://github.com/shesek/btproof)