From:      William Casarin <jb55@jb55.com>
Date:      2019-06-07
Subject:   MiniOTS


code: git clone https://git.sr.ht/~jb55/ots-tools

MiniOTS is a stripped down version of opentimestamps proof files. See
my post on opentimestamps if you're not familiar with it. The goal of
MiniOTS was to make very small OTS proofs, so that you can share them
over twitter, DMs, etc.

Here's what a miniOTS timestamp looks like:


$ otsmini timestamp.ots

    CQWAyoiUZAxumvwu8KTpGfXSAmGip3dNr5jNDaVcKr3nGcN3nBYJqtabWGg4ZQUkLrKEAGK
    3PUv9ZDqfrnJk3AWvhKiwGEkT8QAmjhDNNXLB2HyiHUYAeo9RQbonUpKkEKPgNsBjZxknhSty
    8QMaAZ5ahjcsQmLSr8LV2ZiiSSxrvC4


Let's see what it looks like when decoded back to a normal timestamp:


$ otsmini timestamp.ots | otsmini --decode | tee minified.ots | otsprint

    version 1
    file_hash sha256 7ff0c7d02a0dcaef63105b9f5d99c93adc2f501f4f204dcd5918c4a0acd10b55
    append 5065d9a0de5a108dcbd4714467709574
    sha256
    append aa0d7770962773c4970da6bdc8210dd5
    sha256
    prepend 5bf9ca01
    append ca471b3db3ecc5b2
    attestation calendar https://btc.calendar.catallaxy.com


As we can see it stripped out most of the additional structure to
create a minimal timestamp. We can upgrade this miniOTS timestamp to
get a standalone proof like so:


$ ots upgrade minified.ots

    ots upgrade minified.ots
    Got 1 attestation(s) from https://btc.calendar.catallaxy.com
    Success! Timestamp complete


$ otsprint minified.ots

    version 1
    file_hash sha256 7ff0c7d02a0dcaef63105b9f5d99c93adc2f501f4f204dcd5918c4a0acd10b55
    append 5065d9a0de5a108dcbd4714467709574
    sha256
    append aa0d7770962773c4970da6bdc8210dd5
    sha256
    prepend 5bf9ca01
    append ca471b3db3ecc5b2
    |
    \--> attestation calendar https://btc.calendar.catallaxy.com
    sha256
    append e424667f77714733b6286f01ba69eaf1249fcedbb5d737bad76b5b83015c01ae
    sha256
    append 090b43b44612cef9aa5b91492eb3726aa496700ecb864a9ec7cc3e4b9cc7048f
    sha256
    prepend 3d834e4484331f86f695158d87abc350a0b6e6572f142f5a147dca67e1d51e77
    sha256
    [..]
    sha256
    sha256
    append ab90169d97f24b64b726f894277754d09c8ca027a0b1f6054c2525a1ddfcce91
    sha256
    sha256
    attestation bitcoin height 551387

We can see that the upgrade added a new path to the root path that
eventually hits a bitcoin height attestation. neat!