Password-protected file in Mac OSX
Solution 1:
I believe this program will solve your issue:
BetterZip 1.7.3
BetterZip can open, extract, and create password protected zip files that are compatible with PKZip2 or WinZip's AES256 encryption. Whenever BetterZip needs a password for an operation a panel will drop down and ask for the password. BetterZip can split archives into multiple volumes. Add files and folders to existing archives, update or rename files already in the archive, move files around within the archive, and delete files and folders from an archive. Create new folders inside the archive. Easily search for files and folders by name inside the archive.
Although apparently it costs $20, i was able to download it. Was not installed though, so it may require registration after a certain period.
I recommend you try the TrueCrypt answer also.
I also came across this Tutorial that does not appear to require any third party software.
All you have to do is open your Terminal and cd to the correct directory, then enter
$ zip -e myzipfile.zip file1.txt file2.txt
However, to open a passworded zip file on Mac you require third party software. I found this tutorial that used Zipeg to open the passworded zip.
I did have a friend try it though, and he used
$ unzip myzip.zip
And was prompted for the password.
The tutorial had mixed comments on it, so your version of OS X may vary on the results.
Solution 2:
In the terminal:
zip -e zipname.zip file1.txt other.doc picture.jpg
Then enter a password. The default zip program on Mac couldn't open the file, but The Unarchiver could. You can do unzip zipname.zip in the terminal too, but it's a bit strange with the file paths (wants to save in the place the original files came from).
From this page.
Solution 3:
After some searching around in frustration for a free alternative for a good free archiver with a GUI I finally found Keka.
Open source project on SourceForge. Works like a charm with password-protected .7z-files.
Info off the webpage:
Keka is a free file archiver for Mac OS X
The main compression core is p7zip (7-zip port)
Compression formats supported:
7z, Zip, Tar, Gzip, Bzip2Extraction formats supported:
RAR, 7z, Lzma, Zip, Tar, Gzip, Bzip2, ISO, EXE, CAB, PAX, ACE (PPC)