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0 pointsnadaviv7y ago0 comments

How does that prove the email was sent, though? Couldn't one timestamp the email into the blockchain, without actually sending the email to the other party?

Edit: btw, I released something that utilizes bitcoin's blockchain for timestamping back in 2013: https://news.ycombinator.com/item?id=5790382 (the website is no longer available because better solutions came since, but its up on github[0] and the wayback machine[1])

This has some interesting use-cases, but people tend to overestimate what blockchain timestmaping actually gets you. You can prove that some piece of data existed at some point in time, but that's it. It doesn't prove this data is authentic, that this data was communicated to anyone, that no one else timestamped this data earlier, etc.

[0] https://github.com/shesek/btproof

[1] http://web.archive.org/web/20140430152135/https://www.btproo...

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xpressyoo7y ago· 2 in thread

The insertion is only done once we have received a response from Google servers that the email has been indeed sent (without bounce or other errors).

nadavivOP7y ago

So you're acting as a trusted party to get delivery confirmations from Google? What if Google doesn't confirm delivery, but you decide to write to the blockchain anyway?

Also, won't Google servers return a cryptographically verifiable delivery confirmation? If so, couldn't this be used as the delivery proof directly instead?

xpressyoo7y ago

Yes, we integrate with Gmail and communicate via the official Gmail API.

We only receive response statuses and act accordingly. Moreover, we think it's important for this functionality to make sense to insert the hash corresponding to the integrity of the email, and so make possible for our customers to "prove" they have indeed sent an email with a specific body/subject/...

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