Bitcoin Forum
December 05, 2016, 02:48:16 PM *
News: To be able to use the next phase of the beta forum software, please ensure that your email address is correct/functional.
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: Photo Timestamps?  (Read 2056 times)
PlasticLiving
Newbie
*
Offline Offline

Activity: 4


View Profile
May 12, 2011, 08:13:34 PM
 #1

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!   Cheesy

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)
1480949297
Hero Member
*
Offline Offline

Posts: 1480949297

View Profile Personal Message (Offline)

Ignore
1480949297
Reply with quote  #2

1480949297
Report to moderator
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1480949297
Hero Member
*
Offline Offline

Posts: 1480949297

View Profile Personal Message (Offline)

Ignore
1480949297
Reply with quote  #2

1480949297
Report to moderator
1480949297
Hero Member
*
Offline Offline

Posts: 1480949297

View Profile Personal Message (Offline)

Ignore
1480949297
Reply with quote  #2

1480949297
Report to moderator
PlasticLiving
Newbie
*
Offline Offline

Activity: 4


View Profile
May 17, 2011, 10:59:45 PM
 #2

Initial proof of concept:
http://plasticliving.blogspot.com/2011/05/fun-with-qr-codes.html
matt.collier
Member
**
Offline Offline

Activity: 105



View Profile
May 17, 2011, 11:52:29 PM
 #3

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?
jerfelix
Sr. Member
****
Offline Offline

Activity: 266


View Profile
May 18, 2011, 10:56:27 AM
 #4

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.
foo
Sr. Member
****
Offline Offline

Activity: 409



View Profile
May 19, 2011, 12:31:53 PM
 #5

jerfelix, best first post ever!  Grin

I know this because Tyler knows this.
davout
Legendary
*
Offline Offline

Activity: 1358


1davout


View Profile WWW
May 19, 2011, 12:57:26 PM
 #6

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.

Alex Beckenham
Full Member
***
Offline Offline

Activity: 154


View Profile
May 19, 2011, 01:02:33 PM
 #7

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.

davout
Legendary
*
Offline Offline

Activity: 1358


1davout


View Profile WWW
May 19, 2011, 01:14:46 PM
 #8

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.

Alex Beckenham
Full Member
***
Offline Offline

Activity: 154


View Profile
May 19, 2011, 01:20:49 PM
 #9

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.

davout
Legendary
*
Offline Offline

Activity: 1358


1davout


View Profile WWW
May 19, 2011, 01:46:56 PM
 #10

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

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.
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).

Alex Beckenham
Full Member
***
Offline Offline

Activity: 154


View Profile
May 19, 2011, 02:01:08 PM
 #11

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

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.

Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!