Comment by DenisM | Hacker News Reader

Comment by DenisM | Hacker News Reader

Excellent idea!

- 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.

- 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.

- 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.

- 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.

Keep up the good work!

> - 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.

EXIF metadata is embedded in images and would be calculated in the SHA256 hash. Just add an EXIF tag including your copyright and you're done.

That is correct. Nevertheless it may also be convenient for someone to sign the document after dragging it in the stampd box.

Thanks for your kind words, your valuable comments and very interesting suggestions! Will consider...

One more thing.

Consider publishing all you hashes for each day in a digest to e.g. USENET or other permanent public storage, then hashing all of those daily hashes together and publishing the meta-hash in New York Times. That way even if blockchain fails as a dating method due to forgery, one could use USENET + paper copies of NYT to date any of the documents. As a matter of fact, there is no limit to how many different ways of dating a hash you could add to your service.

Just make sure you're also including a previous day's unpredictable event (stock market activity?), so that both early and late boundaries can be established with confidence.

This would mean that one would eventually have to rely on the NYT which is a "centralized" source of information. According to the bitcoin experts the blockchain cannot be forged, especially if one's transaction is older than a few hours. If the bitcoin community are right about the above and if you think of the blockchain as a non-centrally-relied bulletin that anyone can write anything (as long as they pay the appropriate fees to the bitcoin miners) and that nobody can erase what was written in the past then there should be no need for relying on any other source of information such as the NYT. On the other hand your idea could be useful as a backup, in case something goes wrong in the blockchain technology!

Backup is exactly what I suggested. Don't rely on a single technology, especially if it's crypto.

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