I created a 7zip archive with AES encryption. I included the option to encrypt the filenames. When I updated the file however I am no longer prompted for a password to open the file and can view the filenames without a password. Newly added files are listed with a minus instead of a plus on the encrypted property and their method property shows LZMA without 7zAES as the first set of files have.

I'm using the windows 7zip file manager GUI.

Can anyone tell me if it's possible to update an archive and maitain the encryption status? Or do I have to extract and recreate the archive if I want all files to be encrypted?

1 Answer 1


You will have to unencrypt and the re-encrypt the whole thing. Otherwise it would be like encrypting with two layers, and not one (even if the password was the same and the program allowed it, both of which may not be the case).

  • 1
    It would be nice if this was automated. I would accept that it was necessary but it should at least take care of it, possibly providing a warning that the files will be written to disk temporarily and advise to use a scrubber. I'm pretty sure powerarchiver does this but without any warnings.
    – barrymac
    May 31, 2011 at 16:56
  • I don't know about powerarchiver in particular sorry.
    – soandos
    May 31, 2011 at 16:57
  • Powerarchiver is quite a nice paid for archive utility for windows which supports a great many archive formats including 7z and encryption where possible. Thanks for your answer!
    – barrymac
    May 31, 2011 at 17:02
  • Sounds like winrar, but thats free...
    – soandos
    May 31, 2011 at 17:23
  • Just looking at winrar's web page now and they do indeed support many more formats than they used to so there is probably not much left between them. This one can be scripted for scheduled archiving which I think is rather nice.
    – barrymac
    May 31, 2011 at 17:41

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