I'm making backups of compressed data (using ZPAQ), some compressed archives are large (50 GiB)
I was just going to use
sha3sum -a 512, for example:
sha3sum -a 512 "Total_DOS_Collection-RELEASE#17-[1981-1995].zpaq"
Then storing the value and later periodically checking if the value of the backup is still the same
Then I started wondering if there would be a better/safer/more appropriate/effective method...