I know there are a few people here who might know the answer to this question which has flared up at work (and caused some controversy).
When you create a password protected zipfile, and then try to unzip it, you can open it, and see the file*names* inside it. But to extract the files you need the password.
Or, IOW, it's not possible to create a zipfile which requires the password prompt before opening it ?
I was sure it used to work like that but
formatting link
which is the horses mouth suggests otherwise
Thanks in advance.
Didn't find your answer? Ask the community — no account required.
Information here may be outdated?
J
John Rumm
Standard zip format does not encrypt the meta data, just the file content. So if you want to use zip, create your zip file with an innocuous name, then zip that with encryption.
(7zip *can* encrypt meta data, but then you will need 7z to unzip the resulting file)
B
Bob Eager
password-
Simple solution. Zip the zip file into another one, and turn off compression to save it even trying. Password protect THAT one.
P
Paul
7ZIP supports SFX, like other archivers.
SFX being "self-extracting archives".
By clicking an option, the .7z has a small executable at the head end, with the MZ stuff a usual Windows EXE has. The file decrypts itself and the recipient does not need to add software to the computer.
Tools claiming to understand the format, can step past the EXE part and munch on the payload. (For security reasons, you might not want to execute an EXE from places unknown.) If Linux has an Archive Manager with the 7ZIP support in it, it can open an SFX, without the need for WINE.
7ZIP has one of the AES crypters for protection of .7z. Which is measurably better than some crusty version of WinZIP on an old PC, which is easy to break into.
There were a couple bugs in that part of 7ZIP, which is why a person seeking to do this encryption, would select a modern version. Go to the site and get a new one.
Some version of WinZIP, eventually got decent protection, but you have to verify that. The weak protection methods were so weak, both Google and Kaspersky can scan the files "in real time". The cracking time is virtually zero. A later WinZIP, needs brute force time.
If you ask 7ZIP to make a bog-standard .zip, then the only features they can include, are "standard features" for such a format. Then you'd have to check into the details of WinZIP or PKZip, to understand what the max protection level possible is, and whether metadata is hidden. This is why you'd select the native .7z, add an SFX tick box, to create an archive with AES and no dangling metadata.
It's possible if you bought the RAR product, it would have a similar feature. (RAR is similar to 7ZIP, has a different author, and the part that makes archives costs money.)
*******
The real intellectual puzzle, is how do you get GMail to deliver an attachment to someone :-)
Now, that'll give you a headache. Regular ISP email might be more intelligent about that. Generally, email systems "don't like" bare EXE files as payloads, because the EXE could be a virus vector. But GMail bans just about everything. It doesn't have to make sense, to be blocked. And hiding the payload in an encrypted .7z that they cannot scan, that's a banning as well. They have an excuse for everything.
Certain types of files, including their compressed form (like .gz or .bz2 files) or when found within archives (like .zip or .tgz files)
Documents with malicious macros [which is all of them]
Password protected archives whose content is an archive.
Recursive logic is recursive. "
Try walking through that picket fence.
Worrying about the archive details might be irrelevant, if you can't solve the transport puzzle first.
For a short while, Firefox had a "file send" capability, until someone splashed cold water on them and gave them a clue. Law enforcement is the best reason to shutter such things.
formatting link
"Firefox Send has been decommissioned on September 17, 2020. See 'What happened to Firefox Send?'."
"This is why we can't have nice things. You kids stop jumping on the sofa."
For naive recipients, take your best shot at testing how unpack-able your puzzle is, before sending. You'll either get silence or whining, depending on the recipients disposition.
Paul
B
Bob Eager
On FreeBSD, you just need the tar utility!
A
Algernon Goss-Custard
Paul snipped-for-privacy@needed.invalid posted
You can use it free. I do.
I send ZIP and RAR attachments by gmail all the time, but I send them by SMTP rather than the webmail interface. It seems to work without any problems.
I suppose you could embed the zipfile in a BMP image file using a utility like BMP Hider
formatting link
T
The Natural Philosopher
take the encrypted zip file and encrypt/zip it again?
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required
Report Content
You are reporting this content to the moderators. They will look at it
ASAP.