I have recently begun using tar in Windows. My desire is to eliminate the multiple steps required to create a set of encrypted files suitable for upload for storage.
What I have done in the past;
Before now, my method for achieving this has been to use PGP to symmetrically encrypt a directory, and then use 7zip to create 1GB (or other size) spans of the new .pgp file.
However, I have developed the lazy man's way of using VERY strong 64-byte or 128-byte length passwords with the command-line gpg. It is possible to copy and paste such a password into gpg at the command prompt. Of course, the list of such passwords is itself an ASCII armored file.
But, when using gpg, it is first necessary to zip, ot tar or bzip2 the directory before applying encryption with gpg. After reviewing the documentation on tar, I have failed to use the script provided which should pass the tar through gpg. The scrit provided is as follows:
#! /bin/sh
case $1 in
-d) gpg --decrypt - | gzip -d -c;;
'') gzip -c | gpg -s ;;
*) echo "Unknown option $1">&2; exit 1;;
esac
When I use it, the tar is created in the temp folder (I'm guessing) before passing it through to gpg, just as it does with the command --use-compress-program=bzip2, the cursor suddenly moves to a random location on the screen, a gpg file of zero length is created, and the dos command freezes or hangs or something.
I do not know how to write scripts so I wont even try. Is there a way to tar a directory, pass it through gpg, be prompted by gpg to provide a password, span the .tar file across multiple volumes of equal length all in one line so that I don't have to do it in 2 or three steps?
By the way, I've also experimented with comparing (1) creating a tarball, passing it through bzip2 and then encrypting the resulting file with gpg, with; (2) creating a tarbal, encrypting it with gpg with the commands for using bzip2. the second method created smaller files by almost 1 percent. (I've got 70GB of data to backup and encrypt. That's how I noticed it.) And, the second method is one-third faster, becuase gpg writed directly into the file, whereas tar creates a temp file first, before passing in through bzip2. With 70GB of data, that's probably 3 hours saved.
___________________
Sydney Lewis-Picard
tel. 678-755-7826
fax. 952-255-1468
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