Timestamping signed documents or detached signature files

Stefan Claas stefan.claas at posteo.de
Mon Jul 23 00:17:10 CEST 2018

On Sun, 22 Jul 2018 21:57:13 +0200, Wiktor Kwapisiewicz wrote:
> > Thank you very much for the additional infos and links, i will read
> > them all.  
> Oh, I forgot to mention that timestamping using blockchains is
> actually very easy, for example I timestamped my key's fingerprint:
> https://keyserver.ubuntu.com/pks/lookup?fingerprint=on&search=0x653909A2F0E37C106F5FAF546C8857E0D8E8F074&op=vindex
> (look for timestamp+bitcoin-transaction at metacode.biz 
> afcb092c5ca6409526d18ae9cf22d3b55d37e723eb1b74e3f84f7e6b052a162a)
> And you can check out the transaction here:
> https://blockexplorer.com/api/tx/afcb092c5ca6409526d18ae9cf22d3b55d37e723eb1b74e3f84f7e6b052a162a
> (look for "OP_RETURN 653909a2f0e37c106f5faf546c8857e0d8e8f074" that
> is my key's fingerprint).
> If you convert "time": 1507539820 seconds from there to date you'll
> get something like 2017-10-09T09:03:40.000Z.

Thanks! I also checked the transaction via blockchain.com.

> OpenTimestamps (I think) uses Merkle trees to minimize fees but the 
> downside is that the hash is not directly embedded in the blockchain
> and you need the extra files to reconstruct the tree root.

Yes, and the service is free. In the past i played also with OP_RETURN,
via WWW based services and my Electrum Wallet.

> Have a nice day!

Thanks, have a nice day too! Here it is already very late and i go to
bed now.

Best regards


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