On Sat 23 May 2020 at 23:35:10 (+0200), Hans Åberg wrote: > > On 23 May 2020, at 23:00, antlists <antli...@youngman.org.uk> wrote: > > On 23/05/2020 20:21, Valentin Villenave wrote: > >> I’m not saying the world is a nice place (it isn’t); you should, at > >> the very least, secure*your* copyright by having a solid proof of > >> anteriority, as we discussed. What I’m saying is that you shouldn’t > >> overestimate the possible threat to your work if you were to publish > >> it freely, nor the amount and quality of “protection” you’ll get from > >> any RMO out there. > > > > for the sake of a few pennies, there's an easy way to prove the date. Used, > > I believe, by some law firm in America for its legal documents, and easy > > enough to do here in England too. > > > > Put all of your stuff on a CD. Now run a program that generates an MD5 > > checksum or whatever it is, and save both the command and output to a text > > file. (I'd throw in a listing of the CD too.) Print this, as an advert, in > > a legal newspaper such as - in London - Lloyds Gazette. > > > > That CD can now be copied freely, the MD5 sum won't change. And the advert > > proves that it was in existence on the date of the newspaper. You don't > > even need to save a copy of the newspaper - the fact that it is a newspaper > > of legal announcements means that there will be loads of copies kept, > > probably a lot of them by courts themselves! > > Don’t use MD5 though, as it is not considered secure. SHA-256 and SHA-512 are > better.
Yes, not cyptographically secure. But that's not the threat model, is it? So, I carefully craft a document whose MD5 digest matches the musical work. What shall I do? I've either created another work that the real owner can pass of as theirs, depriving me of the benefit, or I've created a confession of past crimes, which I can hand to the police so that the owner, my rival composer, gets locked up. They don't seem very likely scenarios. However, I don't expect it to cost many more pennies to publish several digests. Cheers, David.