パスワードを使用したzipファイルの問題

zipマニュアルページから、

-P password
       --password password
              Use  password  to encrypt zipfile entries (if any).  THIS IS INSECURE!  Many multi-user operating systems provide ways for any user to see the current command line of any other user; even
              on stand-alone systems there is always the threat of over-the-shoulder peeking.  Storing the plaintext password as part of a command line in an automated script is even  worse.   Whenever
              possible,  use the non-echoing, interactive prompt to enter passwords.  (And where security is truly important, use strong encryption such as Pretty Good Privacy instead of the relatively
              weak standard encryption provided by zipfile utilities.)

マニュアルページで述べたように、これは非常に安全ではありません！

zipしたがって、マニュアルページで次のことをやり直すことができます。

--encrypt
              Encrypt the contents of the zip archive using a password which is entered on the terminal in response to a prompt (this will not be echoed; if standard error is not a tty, zip  will  exit
              with an error).  The password prompt is repeated to save the user from typing errors.

コマンドは次のようになります。

zip --encrypt foo.zip foo.txt端末でパスワードを尋ねるが、

Enter password: 
Verify password: 
updating: foo.txt (stored 0%)

警告する:使用される暗号化技術はzipそれほど強力ではありません。壊れやすい！