Bitcoin Forum

Hi all,

New to this forum, and new to bitcoin in general.  I'm absolutely floored by the potential I see here.  All my friends are sick of hearing about it, but I can't stop talking/thinking about bitcoin!   :D

I had an idea for a service: phototimestamp.org (don't bother going there.  I've registered the domain, but nothing else)

Here's how it works:

You want to prove to someone the 'recency' of a photo.  Lets say you have a rare baseball card for sale.  It's so rare, that many people are going to doubt you are actually in possession of the card.

The classic 'trick' from books and movies is to take a picture of the baseball card, with today's newspaper in the background.  Then others can verify the authenticity of the newspaper, and be confident of the recency of the photo.

But what if the seller is in a foreign country?  If I got a photo of, say, a Chinese newspaper, it would take a significant chunk of time for me to be confident in its validity.

Enter phototimestamp.org.  How it works:

- Every 15 minutes, it generates a time string (YYYY/MM/DD HH:MM).
- It salts the string with randomness, and signs it.
- It then takes the cyphertext, and creates a QR code, which it displays (largly) on the front page of phototimestamp.org
- A seller then navigates to the site, and take a picture of the baseball card with the QR code in the background, and sends it to the buyer
- The buyer sees that, yes, it is the card he's interested in.  He then uploads the photo to phototimestamp.org to find out what the stamp is.

That's the free service, one could also sell 'custom' timestamps that come with a custom message...

What do you guys think?  Is it secure?  Is it useful?  Already done?  I'm still fairly new to this whole bitcoin thing, so I'd appreciate any feedback anyone might have.

I see the potential for something like this to be used with escrow services to minimize risk of transactions (people might even start insuring transactions based on previous ratings, and some sort of proof in this form)

Initial proof of concept:
http://plasticliving.blogspot.com/2011/05/fun-with-qr-codes.html

I can certainly see the value in your idea.  Can you think of a way to ensure that the photo has not been digitally altered?

I like your idea.

You may want to check out the Wikipedia page on Digital Time Stamping.  It may give you some implementation ideas.  http://en.wikipedia.org/wiki/Trusted_timestamping

Digital Time Stamps generally have sort of the opposite purpose than what you describe (they are typically used to prove that something is "old", not that something is "new".  For example, you may invent something today, but you want to prove in court in 5 years that it was indeed invented today.  So you digitally time stamp it.)

In the context of Bitcoin, you could use the Bitcoin block hash code (which a new one is generated approximately every ten minutes) to be your "proof of recency".  For example, take a photo of an item, with THIS QR Code in it [ http://chart.apis.google.com/chart?cht=qr&chs=230x230&chl=http%3A%2F%2Fblockexplorer.com%2Fblock%2F0000000000004b5a4b59a5cbf4098247c7ecc8f58f1434b3ab51fa46e797e4a0 ], and you know that the photo was taken at or after the time I am typing this message (as it's the most recent block hash).

And the date/time is confirmed by block explorer.


(I guess what I am saying is that your application can be done very simply using current block hashes, google QR Code generator, and block explorer.  Not that it doesn't have value, but that you may already be done!)

Hope that helps.

jerfelix, best first post ever!  ;D

I don't really see how that's more convenient than photographing your baseball card with the nytimes.com in background.
Oh wait a minute, the nytimes.com solution doesn't require you to scan any sort of fancy QR code.

My point is that your idea doesn't really solve any problem in a much more elegant way than the outlined solution.

The OP mentioned that it would take a lot of time to authenticate if the newspaper were Chinese... on the flip side, a photo of the NY Times may take a long time for a Chinese/Other person to authenticate.

This is why I specifically mentioned a newspaper website, not a physical newspaper.
If you can scan a QR code and verify a signature with a smartphone, chances are that you can access any newspaper website.

If you went to a Chinese website and it looked exactly like in the photo, how would that help you to know how recent it is?

You could guess that the website is updated every day, but what if it isn't? If the page is completely stale (and only contains foreign language), you'd have no way of knowing how old the photo is.

Obviously it works with *some* websites, the front page of google obviously won't do...

Again, you pick a website for which you don't have to guess.... Again, a famous newspaper will do.

If you want to nitpick go for it, the point is there are much easier ways to solve a not-so-common problem (you'd first be worried about the person actually sending the goods wouldn't you).

My point was only that there is no website so famous that foreigners will be able to read it and validate it (and 'not have to guess'), however a QR code can be embedded in a site of any language.

Hey,

Talking about time-stamp, we are working on a project with copyright protection & marketplace.

The platform offers copyright protection with all copyright information time-stamped using smart-contracts.
Information like author name, country, city and information about the image: encrypted fingerprint along with the published url is recorded on the ethereum blockchain.

Its like a copyright certificate of authenticity.

Sample link to demo image: http://alpha.stockblock.io/stock-photo/syringe-medical-injection-in-hand-palm-or-fingers-7952.html

Etherscan Contract Address: https://ropsten.etherscan.io/address/0x002c3505187974b61ca8235b99f595342cd22ae7#readContract

This is how the basic SmartContract information will look like.

https://i.imgur.com/jDaoBBI.jpg (https://imgur.com/jDaoBBI)

Using SmartContract the author can also receive payments.

Before starting any serious work on your project just try to calculate the potential outcome (but anyway doing something is better than doing nothing). If the project will be used for extremely rare items then the target audience must be tiny if you wont add anything else.

Copyright was sentenced to death by the free internet, your marketplace won't help your potential customers untill they create any unique product.

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