Here's what the Canadian Senate just put in the Bitcoin blockchain:
TEXT:"Senate Banking Committee calls for light touch approach to regulation of Satoshi's invention"
DOCUMENT HASH:81b43c71e2eea227655bd2cf8aba38e18613825bd82332903b1655ead135243d proof of existence
Corresponding to...
DOCUMENTThe Senate Banking Committee's report on digital currency
(background)I'm a Canadian Bitcoin professional. A little while ago Decentral, where I work, was approached by a Senate staffer for assistance in placing a short message and a "proof of existence" into the blockchain on the release of their report about digital currencies. My colleague and I were happy to provide them with technical help. Today both that report and the blockchain message + proof of existence have been publicly released and included in block #361625, as can be verified at the above links.
(technical details)In order to minimise blockchain bloat both the message and the document hash were embedded using OP_RETURN so that full nodes do not have to store the UTXO's in their mempool, as they are forced to with, for example, the aptly-named cryptograffiti approach. The use of OP_RETURN also ensures that these outputs can be pruned from disk storage by non-archival nodes in the future. Due to the small size permitted in OP_RETURN the message was split across three different transactions.
The document hash was embedded using the format from ProofOfExistence.com, though not through the site itself due to a need for clear association between the message and the document hash. To verify the proof of existence, download the file directly from the Senate link and hash it with the sha256 algorithm (for example using the "shasum" tool on linux). Compare the hexadecimal representation of the hash with the hexadecimal string located in the transaction at the "DOCUMENT HASH" link above (mouse over the "Proof of Existence" link on coinsecrets.org to see the hash). They should match!
(in plain language)Mostly for fun, and partly as a nod to the community, the Canadian Senate has embedded the message "Senate Banking Committee calls for light touch approach to regulation of Satoshi's invention" as well as a short cryptographic "timestamp" that will prove to later viewers the document existed at this particular point in time and has not been changed since.
(more about the report)
As posted yesterday evening, this report is the one the Senate banking committee has been working on for quite some time, and in service of which Andreas Antonopoulos, along with many others, have testified before the committee. The conclusion reached by the committee seems to be a largely positive one, saying explicitly that the benefits of this technology outweigh the challenges it introduces and recommending a "light touch" in the regulatory department.
Edit:Confirmation tweet from Senator Doug Black:
https://twitter.com/DougBlackAB/status/611922954885165056