[mprime1]

Indeed. Borg for example is e2e but able to dedupe.

My bookmark archive is 10TB but deduped on-disk size is 100GB because most files are the same across backups!

https://www.borgbackup.org/

[orf]

That’s not the same thing at all.

[mprime1]

Same thing as what?

Parent was asking about deduping encrypted data.

Someone said (wrongly) it’s impossible and I shared a popular project that does exactly that.

[orf]

“Not backing up the same file twice” is not the same thing as deduplicating encrypted data, as encryption has no relevance there. You can do that with or without encryption.