Some of the time a screenshot is used to prove that something was posted on a website, it's handy if you think the post might be taken down and you need to prove it was up later on. The problem? Screenshots are easy to fake.

Enter a web service that, for a fee, takes a screenshot of a webpage for you, timestamps it and holds it in their trustworthy 3rd party server. Over time the company would gain the trust of the public and a reputation for being the de-facto method for proving that content (including pictures) was up on a given website at a given time. This site would be high quality enough and trustworthy enough to make it useful in court, or perhaps just in protracted flamewars.

I know there are internet archives, but these are slow, I want something that works "on demand."

*By the way if this is baked I plan to take this idea down, but you'd better get a screenshot or you can't prove I ever posted it! Nah na na nah nah!
-- futurebird, Jun 22 2008

Cryptographic hashes http://www.unixwiz....-crypto-hashes.html
I didn't know. Now I do. [bungston, Jun 23 2008]

Sort of like the Wayback Machine, but on demand.
-- phoenix, Jun 22 2008


why would you need to prove that you posted something in court?

I would more likely need to prove that I did not post something.
-- dev45, Jun 23 2008


//I would more likely need to prove that I did not post something//

I did not post that ;)
-- dev45, Jun 23 2008


The way to solve that last problem would be to rely on the party that wants to check whether something was up on address X to supply the screen shot themselves. (E.g., it would be part of the court documents.)

1. You buy a slot on verifyimage.com. You give them a URL.
2. They give you a rendered version of the page at the URL, perhaps with the source HTML as well. At the same time, they store a SHA-1 hash of that data on their server with a timestamp.
3. You give the rendered image and the URL to the judge.
4. The judge uploads the image to verifyimage.com, and asks about the URL and timestamp.
5. Verifyimage.com compares their stored SHA-1 hash with the hash stored for the given URL. If they match, the URL rendering is proven for the given timestamp.
-- jutta, Jun 23 2008


I wonder if hashed data from a screenshot would differ depending on what one used to obtain the screenshot. I would think it would have to. If you hashed only the characters you would get no data about images. If you broke screenshot images down to data, the data would differ between a highres and lowres screenshot.
-- bungston, Jun 23 2008



random, halfbakery