### Please describe the problem.

every sync (without --content) to a gcrypt remote uploads huge amount of data (>100MB) when doing

    gcrypt: Requesting manifest signature

It seems to upload a special git object every time, even if this object is apparently unchanged. An unencrypted, regular git remote is much faster and does not transfer such amounts of data.

I wonder if this can be changed, because it renders that gcrypt remote almost unusable via ADSL upstream. In my case the sync duration was 36 Minutes, uploading ~250MB.

### What steps will reproduce the problem?

Have a (bare) gcrypt remote and a rather big (mine has 77668 keys, annexing 769GB of files) git-annex repository. Sync with the gcrypt remote. When pushing, the message "gcrypt: Requesting manifest signature" appears, and a very large amount of data is transferred to the remote, while the process chain

    git-remote-gcrypt mygcrypt ssh://mygcrypt/home/my/annex
     git push --quiet -f ssh://mygcrypt/home/my/annex refs/gcrypt/gitception+:refs/heads/master
      ssh mygcrypt git-receive-pack '/home/my/annex'
       git pack-objects --all-progress-implied --revs --stdout --thin --delta-base-offset -q

is running. The upload of the actual changeset starts after this, the processes look the same, transferring again a more or less big amount of data (depending on the changeset size, I guess).

### What version of git-annex are you using? On what operating system?

6.20170101-1 on Debian Stretch (9.0)

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

git-annex is great and revolutionized my file organization and backup structure (if they were even existing before)

[[!meta title="gcrypt special remotes should support rsync:// and perhaps also sftp://"]]
