Now it is clear!
I always trusted a lot rclone and the storage, but I was looking at something to check the data I have in the cloud compared to the ones I have locally.
Since the data in the cloud are encrypted, the suggestion I got is to download, decrypt and compare, that is time consuming.
is this the only way?
If the answer is yes, this is the only way, then after reading your answer, I the possible soultion would be:
a) get the checksum of the file encrypted and stored in the cloud
b) encrypt the local file with the nonce of a)
c) compare the checksum of the local file with the one of a)
any idea how to do that?