send encrypted archive from windows machine to a mac osx user

Question

I want to send a file to a friend by email, password encrypted.

On my windows machine I used 7zip and tried zip and bzip2 together with aes 256.

My friend on Mac Osx cannot open it. A window shortly pops up and closes. On the command line he receives the error message "... need PK compat. v5.1 ..."

He is not a computer wizard and I would like to find a solution where he does not need to install anything - if possible.

What is the simplest way to send a password encrypted file from win to osx?

Answer 1

I know you say that you don't want to recipient to have to install anything, but you also say he is not a "computer wizard". Options:

• use Mac built in OpenSSL routines at command line (ala this SuperUser post)
• use a naive user friendly app, such as BetterZip (not free) or iZip (free)

Answer 2

Use something other than AES, as it's support in Zip archive programs is limited.

Perhaps just use ZipCrypto instead of AES, as it's support by all unzip programs, including the ones built into current OSes.

It's not as secure, but it's still probably more than enough for what you're doing.