IMAGESIGN(1)		   User Manuals		     IMAGESIGN(1)

NAME
       imagesign - digitally sign an image

SYNOPSIS
       imagesign [-v] [-u USER] [FILE]...

DESCRIPTION
       imagesign  is  a	 utility for digitally signing images in-
       place, such that the images may continue to be viewed with
       a normal viewer.

       If  you	or your organisation regularly produce images and
       you need to be able to tell later on whether an image  has
       been modified from the original, or you need to be able to
       pass the images on to other people and  they  need  to  be
       able  to	 check whether it really is you who sent them the
       image, then this utility may be useful to you.

       It works by signing the image itself  (not  including  any
       comment	blocks) using gpg(1), and then embeds that signa-
       ture in the image within a comment  block.   This  comment
       block does not affect the image in any way.

       Once the image has had a signature embedded in it, you can
       send it, store it, or whatever, treating it  as	you  nor-
       mally would.  However, as soon as the image is modified in
       any way (even if it is just loaded and saved  again),  the
       signature  will	no longer be valid and imagesign --verify
       will tell you that the image is not the original that  you
       signed.

OPTIONS
       Options	are read in order, from left to right, so you can
       sign some images and verify some others in the  same  com-
       mand line if you particularly want to.

       -v, --verify
	      Verify the signatures of the given images.  An exit
	      code of 1 (failure) means that one or more  of  the
	      images failed the signature check.

       -u USER, --local-user USER
	      When  signing,  sign as USER instead of the default
	      user.  This option is basically passed directly  on
	      to gpg(1) as-is, and applies to all files specified
	      on the command line from this option onwards.

       -h, --help
	      Print a usage message on standard output	and  exit
	      successfully.

       -V, --version
	      Print  version  information  on standard output and
	      exit successfully.

AUTHOR
       Andrew Wood <andrew.wood@ivarch.com>
       http://www.ivarch.com/

BUGS
       If you find any bugs, please contact the author, either by
       email or by using the contact form on the web site.

SEE ALSO
       gpg(1), rdjpgcom(1), wrjpgcom(1)

LICENSE
       This  is	 free  software,  distributed  under the ARTISTIC
       license.

Linux			  November 2002		     IMAGESIGN(1)
