[[!comment format=mdwn
 username="https://www.google.com/accounts/o8/id?id=AItOawnx8kHW66N3BqmkVpgtXDlYMvr8TJ5VvfY"
 nickname="Yaroslav"
 subject="add MD5SUM (with E) backend?"
 date="2015-01-29T22:07:40Z"
 content="""
probably in many cases MD5SUM might be sufficient to cover the space of the available load and 

- its size would be even smaller than SHA1 (thus smaller git-annex footprint)
- immediate matching to often distributed MD5SUMs
- matching to ETags (whenever wasn't a multipart upload) in S3 buckets

or use of MD5SUM hash is really not recommended for non-encryption-critical cases too?
"""]]