actually, I am trying to do digital watermarking. can you please giv me some hints of algos which i can use to do watermaking on numbers ? like i have array of numbers, then i want to water mark them with some kind of algo and also want to save that watermark which i will get so as to verify it in future.
P.S I am asking for any code here, i am just asking for hints of ALGOS, as i am novice in watermaking. thanks in advance.
I am not aware of any way to watermark numbers. Or maybe I am misunderstanding your question.
If you just want to save an array of numbers, and make sure they have not been altered in any way when you want to use them again, a couple ideas come to mind:
Save them in a Word document and password protect the document. Word also offers the option of adding a watermark to a document, but that isn't relevant to the security of the document.
Alternately, save the array of numbers in a PDF document and digitally sign the document. Then, in the future, if you have to use those numbers again, you will be able to tell if the document has been adjusted at all (or not). It will tell you if the document has been tampered with in any way.
From the Wikipedia article on digital watermarking:
A digital watermark is a kind of marker covertly embedded in a noise-tolerant signal
What algorithm you use depends on what kind of data you're watermarking. For example, if it's an image, you can usually add a watermark by replacing low bits at each pixel with a different image.
If your data aren't noise-tolerant, then you may want something like a digital signature instead.
sir, I have already written that my data is in number form. Can you tell some algod related to that ?
@ David, you haven't got what am asking about. thanks.
sir, I have already written that my data is in number form. Can you tell some algod related to that ?
All data are "in number form." Watermarking relies on you being able to slightly modify your data while not losing anything important. There is no generic "watermark these numbers" algorithm like you seem to be asking for; what is important to a given set of numbers depends on what they represent.
So the next question is: What do your numbers represent?
@ David, you haven't got what am asking about. thanks.
Actually, you seem a little confused yourself about watermarking. I think DavidB's response is reasonable given how you asked your question. Specifically, this:
want to save that watermark which i will get so as to verify it in future.
Watermarking modifies data. There is nothing separate to save and use for later verification; that would be a digital signature.
Are you able to restate your needs without naming specific techniques or solutions? In other words, what purpose do you think a watermark will fulfil for you? If watermarking is a hammer, your problem may not actually be a nail.
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