Hello OTS people,

Following from my previous post about cleartext OTS proof sharing[1],
I've been working on a new OTS format called miniOTS, which is
minimal/compressed format that allows attestations to fit in a tweet[2]
and for other space constrained contexts.

Just stripping out additional attestations in the standard format only
gets it down to just above ~280 bytes when base58 encoded, which is too
much for a tweet, so I decided to roll a custom format that is a bit
more efficient with attestation and op tags.

The goal was to have small enoughs proofs that I could reply to a tweet
with the stamp of the previous message, instead of relying on external
sites such as @otsproofbot


Current format (210 bytes, 288 bytes base58-encoded):

00000000: 004f 7065 6e54 696d 6573 7461 6d70 7300  .OpenTimestamps.
00000010: 0050 726f 6f66 00bf 89e2 e884 e892 9401  .Proof..........
00000020: 08cb 2d4a f572 8d44 a5b0 7c7b f1ff 78a9  ..-J.r.D..|{..x.
00000030: 1818 7270 13f1 9bbd f4b0 344b 9e93 0c6b  ..rp......4K...k
00000040: 39f0 1020 34fe cad9 edef bab0 3420 e4ee  9.. 4.......4 ..
00000050: d3a7 c608 fff0 107c 31f7 da6c dbf2 3271  .......|1..l..2q
00000060: 904c c5dd f58d eb08 f120 e4f7 3eaf a747  .L....... ..>..G
00000070: 324a f096 1aa0 928d e1c1 91bf 3c38 237d  2J..........<8#}
00000080: d412 c1c0 e94c d4ae 3f76 08f1 045c 4cb3  .....L..?v...\L.
00000090: a4f0 08f7 834d 4b14 68fd 41ff 0083 dfe3  .....MK.h.A.....
000000a0: 0d2e f90c 8e2c 2b68 7474 7073 3a2f 2f62  .....,+https://b
000000b0: 6f62 2e62 7463 2e63 616c 656e 6461 722e  ob.btc.calendar.
000000c0: 6f70 656e 7469 6d65 7374 616d 7073 2e6f  opentimestamps.o
000000d0: 7267                                     rg

miniOTS format (133 bytes, 183 bytes base58-encoded):

00000000: 6f74 7301 8a20 34fe cad9 edef bab0 3420  ots.. 4.......4
00000010: e4ee d3a7 c683 8a7c 31f7 da6c dbf2 3271  .......|1..l..2q
00000020: 904c c5dd f58d eb83 8be4 f73e afa7 4732  .L.........>..G2
00000030: 4af0 961a a092 8de1 c191 bf3c 3823 7dd4  J..........<8#}.
00000040: 12c1 c0e9 4cd4 ae3f 7683 8b5c 4cb3 a48a  ....L..?v..\L...
00000050: f783 4d4b 1468 fd41 9a2b 6874 7470 733a  ..MK.h.A.+https:
00000060: 2f2f 626f 622e 6274 632e 6361 6c65 6e64  //bob.btc.calend
00000070: 6172 2e6f 7065 6e74 696d 6573 7461 6d70  ar.opentimestamp
00000080: 732e 6f72 67                             s.org


base58 before:

12j6JNmon36jC1MMcpvC8nHqg5p8DAT2mmPQ5aLaBmAbk8naEVt8HFVohRqkuMXZF2Wo2n9kv
5ByeL17yUww4NHuFyCT6PXsGxRuEZ12Z33gsLbXL5FuFmnvMLd3tzf76n69J7qxLPxmoAgm1z
9NEMi2MRypDNKy1GypGN5NLwerzy1nU5g5dZxV6TZ5rBs4gYqnMNJn9VMkfKeDSZ9M8aoMWrL
ShokXUpnS1qrqkTvTwyKMx17fhKfcP9FyhNkb81t8dwYLtBsN4QuP9UAktMUvjEoBzHt

base58 after:

6gQjQUehytgUevKLRtAFYbC6UJX72LCDgVWxAUPsCt3tqEVTEQfmUB1T1Y1GTyY8sugiPY97K
gWRPPXYJmH3J5jqVtyNLrzdkySM6VAYDVckya9BxbUbFB8Gs4U3LHEauTmgCPEhGhiRdC3eFW
63SwfAvKB8Q8Ku8ZM9uASCwWZ8K2AoVabuAn


You can check it out here:

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

This is still a work in progress, I haven't built the miniOTS -> OTS
decoder yet.

make
./otsmini file.ots


Cheers,
Will


[1] id:878t1fzn0v.fsf@jb55.com
[2] https://twitter.com/jb55/status/1136260220521336832