Jerry Lucas wrote in part "To make things more confusing, in computer architecture, they also use the term notary. But they are referring to a computer (notary server or cybernotary) that verifies the validity and integrity of an electronic document by doing a hash calculation of the content and time stamp."
I wouldn't put it that way. If a hash has been stored in a good blockchain, or other reliable place it shows that the document that processes to that hash existed at the time it was stored in the reliable place, and hasn't been changed since. It doesn't prove the document is true, that it was signed by the person it purports to have been signed by, or anything along those lines.
Sometimes, existence is enough. Suppose I sing a song on TV and Joe Blow claims he wrote the song in 2012. I produce a PDF with sheet music and lyrics, and the hash of the PDF was published in the classified ads of the New York Times in 2005, at which time Joe Blow was 3 years old. Joe Blow's claim is defeated.
But usually mere existence on a specified date is not enough to prove the "validity and integrity" of an electronic document. |