# GUM v.1.0.0

# 25

# Cryptographic filters

So, you want to be a double 0 seven? Then you may want to use these filters to encrypt and hide your information

## Digital Signature

This plug-in lets you make or read an invisible signature in the image. In order to read a signature just press read. If you want to create a signature, you have to fill in the information in the dialog and press write. You must remember to save the image in a non-destructive format like TIFF. If you save it as a JPEG the signature will be destroyed.

## Encrypt/Decrypt:

This plug-in makes it possible to encrypt your images, so no one besides yourself can see them. To encrypt the image, bring up the filter and type your password e.g. "qwerty". To decrypt, bring up the filter again, type your password and the image will get decrypted.

A warning by the author of this filter; Daniel Cotting: This filter may work for you, but there are no guarantees (for us at Frozenriver, this filter has worked with fine). Remember not to save the image in a destructive file format, e.g JPEG. You can enable backwards compatible with the 1.0.X versions of this plug-in, but I suggest to stick with 2.X and not enable this feature if you haven't any images encrypted with the 1.0.X version. You can enable the plug-in to remember your password, but don't forget that passwords are best kept in your own mind where no one can see it.

## Stegano

This filter lets you hide or read a hidden file inside your image. If you want to read the hidden file, press read. If you want to hide a file, just press write and then browse. Remember that if you want to hide a big file then you have to use a big image. As with the other encrypt filters you can't save your image in a destructive file format like jpeg. (This filter is perfect for secret agents like 007 ;-).

Generated by fmtoweb (v. 2.9c) written by Peter G. Martin <peterm@zeta.org.au> Last modified: 19 May 1998