Thread Subject: coding help for secrect key

hi..
im very new to matlab..
i need tis help...
how to embed a image into the lowest order integer of the other image? ie. how to calculate the lowest order integer of an image?

how to use secret key while embedding?
and then how the secret key should be in matlab? give some examlpes for it..so that to provide security of the image from tampering or avoid attacts...

pls give any example code u have for tis query n help me out soon..

prior thanks
-smitha

Dear smitha!

> how to embed a image into the lowest order integer of the other image? ie. how to calculate the lowest order integer of an image?
>
> how to use secret key while embedding?
> and then how the secret key should be in matlab? give some examlpes for it..so that to provide security of the image from tampering or avoid attacts...

This sounds funny and is therefore hard to answer (at least for me).
1. What do you mean by "the lowest integer of an image"? Without an exact definition, an answer is impossible.
2. What is "embedding" and what should the secret key be used for?
3. What is the meaning of "how should the secret key be in matlab"?
4. What is your intention: You want to avoid attacs on an image? Do you need a digital signature to ensure that the image contents is not modified? Or to be more exact: you cannot avoid attacts at all, but there are some techniques to detect attacs.

So if you need answers, give us a chance.
Kind regards, Jan

Sounds to me like he's talking about steganography. But this is too
big a field to answer in a simple newsgroup message. smitha should do
some up front research first, perhaps starting here:
http://iris.usc.edu/Vision-Notes/bibliography/char991.html#Halftone%20Images,%20Compressed%20Images:%20Image%20Hiding,%20Data%20Hiding,%20Steganography

Then search the File Exchange and newsgroup for steganography.

Dear ImageAnalyst, dear smitha!

I got the feeling, that the posting is always a perfect example for hiding information in the least significant bit of a data chunk:

"pls give any example code u have for tis query n help me out soon.."

I'm trying to answer some questions in this newsgroup and read a lot of postings. English is not my mother language as for a lot of other members. But I'm trying hard to be easy to understand. It would be helpful for me -and others- if you use non-compressed full entropy English. Then I can focus on the problem and not on enciphering your question.

Thanks, Jan

hi sir,
        sorry for not being clear in my question!
       i am doing a project in fingerprint authentication using DWT and watermarkin techniques,now we are in the embedding process.
     my doubt is,
      1.how to generate a secret key?
      2.after generating the key how to embed into an image?
  pls do reply as soon as possible

regards,
   smitha