JanetK_CA, yes, the way "notary" is used in much of the digital world, all that is proved is that a certain message digest existed on a certain date. The blockchain serves as the timestamp. If the message digest is found in between a blockchain entry with the timestamp Nov. 19, 2019, 3:20 PM PST, and Nov. 19, 2019, 3:30 PM PST, you know the date and time to within 10 minutes. There are other good ways to provide a timestamp.
To get this kind of "notary", there is no need to have anyone sign the document, nor is there any need for the document to be notarized. Looking at the blockchain, you can't tell if the document is a pretty landscape picture, a grant deed, or the latest from Wikileaks.
It's quite useful for copyrights. Suppose I sing a song and someone complains it's their song; they composed it in January, 2019. But I provide an MP3 of me singing the song, and the message digest matches one that was put on a reliable blockchain in 2015; the complainer's case goes up in smoke. |
