<p><pre><code> Your document titled: hello world is about to be stampd on the blockchain.
Please proceed with payment of EUR 1.49 through Paypal by clicking on the button below.
After payment and the appropriate blockchain transaction transmittal, a PDF
certificate will be sent to your email address as registered in Paypal.
</code></pre>
It would be nice to support payment with bitcoin. Also in addition to emailing a receipt, let users download a receipt right there.<p>Also I'm not sure what exactly a webapp is needed for. I wouldn't use it for anything important. How do I know without looking through your client side JS that you're not sending a copy somewhere? It would be nice to write an open source app, stamp that app's hash in the block chain, and then use that stamped app to stamp other documents, all locally. Or keep the web version too as an alternative. If you want to make money off of that, provide some enterprisey tools for people to verify previously stamped documents or other value-add services not related to the core offering. I think you're losing 99% of early adopters with a fee (is that essential to pay miners or something?).<p>edit: It seems like I'd need a way to verify my identity as part of this hash for it to be of value. Can your certificates be forged? A verifiable and un-forgeable certificate would be valuable. Or perhaps I associate a BTC wallet id with a small amount of money in it and that's part of the overall document hash too. So when I want to prove I hashed it, I send a tiny fraction of a bitcoin from that wallet (and it could be an unpredictable fraction, to serve as a one time PIN). Making all that easy to verify for someone like an underwriter or lawyer could be a nice way for you to make money.
Just paid to stamp a document and thought the process was very easy - nice job!<p>Question: Help me understand the bitcoin financial transaction - I'm not well-versed in bitcoin. In blockchain.info I see "Total Input: 0.0002 BTC" and "Fees: 0.0002 BTC". Is my assumption correct that you had to make a minimal legitimate bitcoin transaction to appear in the ledger (.0002BTC / $0.05), then pay that same amount again as a fee, costing you roughly $0.10USD?<p>More simply, how much bitcoin is being transacted and who is it going to/from in order for you to create the stamp?
Excellent idea!<p>- I'm not sure about E1.50 price, I think $0.99 would be easier to swallow, psychologically. I understand you have the transaction cost weighing on you, so maybe sell packs of 5 signatures for $4.95? This also gives you ability to run promotions with discounted signature packs.<p>- Alternatively a monthly subscription could be interesting as well. Imagine if I'm writing a novel, I might want to keep signing different copies as I go along many times per day, but then rewrite them anyway as I'm not yet satisfied. It would be nice if you shipped a simple text editor that saves all local copies of the work as it's modified, together with persons's name and your timestamp / signature, as a proof of concept. You could be delaying or batching transactions to offset the bitcoin tx cost.<p>- I liked the easy drag and drop for a picture, but sadly I have to put my signature into the picture which takes away all of the drag-drop convenience. It would be more convenient if it worked by me drag-dropping the picture and then typing in free-form text into your web site, such as "Copyright (c) DenisM aka foo@bar.com", and then you hashing (picture + signature), detailing the procedure in the PDF.<p>- In a weird way contradicting the convenience aspect I just asked for, I would prefer to give you my hash of the document rather than document itself. I may be afraid of the content leaking before I am ready to release it myself. It's an easy fix for you - add a separate tab where instead of dropping the document I can paste in the hash myself.<p>Keep up the good work!
stampd.io is a web application which helps you apply a blockchain stamp on your art or creative content in general. I would be very happy to hear your comments, suggestions or any questions if you have the time to spare a look. A blockchain stamp can allow you to certify the existence of your content at a specific point in time. If your content is original it can also allow you to prove unquestionable ownership without having to rely on any third party service or authority.
We are confident that this new technology can revolutionize the intellectual property rights of creative content.<p>The time stamping used in stampd's process is carried out in a way through which the user is able to undeniably prove the stamping in the future without relying in our service (or to anyone else's).<p>Any user of stampd, just by having in hand:<p>(a) his electronic file (the one with the original content and his signature)
(b) the PDF certificate that we issue after stamping which explains all the technical details of the stamping on the blockchain.<p>...may prove his stamping to anyone needed in the future, simply by using the above and any of the available blockchain explorers.<p>We would be glad to hear your impressions or any suggestions you might have.
Some FOSS projects should stamp their git master commit hash regularly to protect their ideas against future patents with proving prior art. CAs' timestamping services are far more expensive.