hm what compression algorithm to use

am sure some of u tards are creating encrypted file stores to upload to free cloud services like dropbox

what happens when u modify the archive (adding, removing, moving, renaming ARMR)

even if one simply renames a single file inside the archive, it must rebuild entirely

then u must reupload the entire thing

are there any algorithms that rebuild 'inplace' or some shit, how do i do this

currently using tar with no compression.. i haven't actually looked at the structure of the tar file. is it just the dropbox client's fault?