Most workplaces install a third party compression utility on top of W$. All
those I know of and Apple stuff understand GZIPed TAR named .tgz. If yours
haven't get the admins to install 7-zip which AIUI is free software.
Otherwise you'll probably run into problems with some older machines still
having the 4GB zip boundary problem. .tar.gz is a better format for all and
doesn't have the4GB problem. If they've got 7-Zip you can also use .tar.xz
for even higher compression.
My personal preference for encrypting archives is to use GPG. Then you've
got more control over who can open it than just a password. Plus, as you can
tell from Internet Banking routinely requiring you use a token if you want to
be able to transfer noticeable amounts of money, a password alone is not
great security.
Domestic users generally value convenience too much for strong security
measures which really need admin time to do it properly, e.g. how many of the
people here check their logs for signs of intrusion? With the reputation of
China's security services being they're actively interested in industrial
espionage over the Internet and with so many intrusions reported publicly in
goverment reports each year I wouldn't advise any workplace to rely on just
passwords for any data at all.
