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I originally was using WinZip15 to create .ZIP files with AES256 which we later package into .EXE files using WinZip's self extracting tool (since we can't be sure the people we are giving the archives to will have a zip utility that can handle AES-256 ZIP archives).

I started using 7Zip's command line utility to package the ZIP files using

7za a -y -tzip -ptestabc123 -mem=AES256 C:\helloworld.zip C:\test\

Is there anyway to tell if it actually used AES256 to encrypt the archive? It clearly has a password, but other than that it seems difficult to determine. When I created AES256 archives using WinZip15 "View in explorer" did not work, which I presume is normal. When I create archives using 7za (with the -mem=AES256 switch), windows explorer CAN open the zip archive which I find strange.

Jai
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  • It is not encrypting the whole file, rather the individual files inside the main archive which is not encrypted, that's why you can see the file names but can not see their contents – Johnydep Jan 16 '12 at 18:09
  • Just for the record; Encryption with zip files has nothing to do with listing the compressed filenames. It takes effect only in compression algorithm. – vegatripy Mar 22 '16 at 17:07
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    You can use technical info listing which shows encryption method: `7z l -slt c:\helloworld.zip` – Pierz Mar 19 '18 at 12:21

1 Answers1

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I don't know about 7zip, but you can create a self-extracting EXE that uses AES56, using DotNetZip's command line tools.

Cheeso
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  • I started using DotNetZip's lib in my C# project. I forgot about this question, but you reminded me how happy I am to have it. – Jai Mar 24 '11 at 18:32
  • https://superuser.com/questions/160672/what-is-7-zip-s-command-line-argument-to-create-a-self-extracting-archive – cardamom Jul 20 '21 at 18:47