-
@ jb55
2025-06-03 14:45:176 years ago I created some tools for working with peter todd's opentimestamps proof format. You can do some fun things like create plaintext and mini ots proofs. This short post is just a demo of what these tools do and how to use them.
What is OTS?
OpenTimestamps is a protocol for stamping information into bitcoin in a minimal way. It uses OP_RETURN outputs so that it has minimal impact on chain, and potentially millions of documents are stamped all at once with a merkle tree construction.
Examples
Here's the proof of the
ots.csource file getting stamped into the ots calendar merkle tree. We're simply printing the ots proof file here withotsprint:``` $ ./otsprint ots.c.ots
version 1 file_hash sha256 f76f0795ff37a24e566cd77d1996b64fab9c871a5928ab9389dfc3a128ec8296 append 2e9943d3833768bdb9a591f1d2735804 sha256 | --> append 2d82e7414811ecbf | sha256 | append a69d4f93e3e0f6c9b8321ce2cdd90decd34d260ea3f8b55e83d157ad398b7843 | sha256 | append ac0b5896401478eb6d88a408ec08b33fd303b574fb09b503f1ac1255b432d304 | sha256 | append 8aa9fd0245664c23d31d344243b4e8b0 | sha256 | prepend 414db5a1cd3a3e6668bf2dca9007e7c0fc5aa6dc71a2eab3afb51425c3acc472 | sha256 | append 5355b15d88d4dece45cddb7913f2c83d41e641e8c1d939dac4323671a4f8e197 | sha256 | append a2babd907ca513ab561ce3860e64a26b7df5de117f1f230bc8f1a248836f0c25 | sha256 | prepend 683f072f | append 2a4cdf9e9e04f2fd | attestation calendar https://alice.btc.calendar.opentimestamps.org | --> append 7c8764fcaba5ed5d | sha256 | prepend f7e1ada392247d3f3116a97d73fcf4c0994b5c22fff824736db46cd577b97151 | sha256 | append 3c43ac41e0281f1dbcd7e713eb1ffaec48c5e05af404bca2166cdc51966a921c | sha256 | append 07b18bd7f4a5dc72326416aa3c8628ca80c8d95d7b1a82202b90bc824974da13 | sha256 | append b4d641ab029e7d900e92261c2342c9c9 | sha256 | append 4968b89b02b534f33dc26882862d25cca8f0fa76be5b9d3a3b5e2d77690e022b | sha256 | append 48c54e30b3a9ec0e6339b88ed9d04b9b1065838596a4ec778cbfc0dfc0f8c781 | sha256 | prepend 683f072f | append 8b2b4beda36c18dc | attestation calendar https://bob.btc.calendar.opentimestamps.org | --> append baa878b42ef3e0d45b324cc3a39a247a | sha256 | prepend 4fb1bc663cd641ad18e5c73fb618de1ae3d28fb5c3c224b7f9888fd52feb09ec | sha256 | append 731329278830c9725497d70e9f5a02e4b2d9c73ff73560beb3a896a2f180fdbf | sha256 | append 689024a9d57ad5daad669f001316dd0fc690ac4520410f97a349b05a3f5d69cb | sha256 | append 69d42dcb650bb2a690f850c3f6e14e46c2b0831361bac9ec454818264b9102fd | sha256 | prepend 683f072f | append bab471ba32acd9c3 | attestation calendar https://btc.calendar.catallaxy.com append c3ccce274e2f9edfa354ec105cb1a749 sha256 append 6297b54e3ce4ba71ecb06bd5632fd8cbd50fe6427b6bfc53a0e462348cc48bab sha256 append c28f03545a2948bd0d8102c887241aff5d4f6cf1e0b16dfd8787bf45ca2ab93d sha256 prepend 683f072f append 7f3259e285891c8e attestation calendar https://finney.calendar.eternitywall.com ```
The tool can create a minimal version of the proofs:
``` $ ./otsmini ots.c.ots | ./otsmini -d | ./otsprint
version 1 file_hash sha256 f76f0795ff37a24e566cd77d1996b64fab9c871a5928ab9389dfc3a128ec8296 append 2e9943d3833768bdb9a591f1d2735804 sha256 append c3ccce274e2f9edfa354ec105cb1a749 sha256 append 6297b54e3ce4ba71ecb06bd5632fd8cbd50fe6427b6bfc53a0e462348cc48bab sha256 append c28f03545a2948bd0d8102c887241aff5d4f6cf1e0b16dfd8787bf45ca2ab93d sha256 prepend 683f072f append 7f3259e285891c8e attestation calendar https://finney.calendar.eternitywall.com ```
which can be shared on social media as a string:
5s1L3tTWoTfUDhB1MPLXE1rnajwUdUnt8pfjZfY1UWVWpWu5YhW3PGCWWoXwWBRJ16B8182kQgxnKyiJtGQgRoFNbDfBss19seDnco5sF9WrBt8jQW7BVVmTB5mmAPa8ryb5929w4xEm1aE7S3SGMFr9rUgkNNzhMg4VK6vZmNqDGYvvZxBtwDMs2PRJk7y6wL6aJmq6yoaWPvuxaik4qMp76ApXEufP6RnWdapqGGsKy7TNE6ZzWWz2VXbaEXGwgjrxqF8bMstZMdGo2VzpVuEyou can even do things like gpg-style plaintext proofs:
``` $ ./otsclear -e CONTRIBUTING.ots -----BEGIN OPENTIMESTAMPS MESSAGE-----
Email patches to William Casarin jb55@jb55.com
-----BEGIN OPENTIMESTAMPS PROOF-----
AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC/ieLohOiSlAEILXj4GSagG6fRNnR+CHj9e/+Mdkp0w1us gV/5dmlX2NrwEDlcBMmQ723mI9sY9ALUlXoI//AQRXlCd716J60FudR+C78fkAjwIDnONJrj1udi NDxQQ8UJiS4ZWfprUxbvaIoBs4G+4u6kCPEEaD8Ft/AIeS/skaOtQRoAg9/jDS75DI4pKGh0dHBz Oi8vZmlubmV5LmNhbGVuZGFyLmV0ZXJuaXR5d2FsbC5jb23/8AhMLZVzYZMYqwjwEPKWanBNPZVm kqsAYV3LBbkI8CCfIVveDh/S8ykOH1NC6BKTerHoPojvj1OmjB2LYvdUbgjxBGg/BbbwCGoo3fi1 A7rjAIPf4w0u+QyOLi1odHRwczovL2FsaWNlLmJ0Yy5jYWxlbmRhci5vcGVudGltZXN0YW1wcy5v cmf/8Aik+VP+n3FhCwjwELfTdHAfYQNa49I3CYycFbkI8QRoPwW28AgCLn93967lIQCD3+MNLvkM jiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ/AQ3bEwg7mjQyKR PykGgiJewAjwID5Q68dY4m+XogwTJx72ecQEe5lheCO1RnlcJSTFokyRCPEEaD8Ft/AIw1WWPe++ 8N4Ag9/jDS75DI4jImh0dHBzOi8vYnRjLmNhbGVuZGFyLmNhdGFsbGF4eS5jb20= -----END OPENTIMESTAMPS PROOF-----
$ ./otsclear -v <<<proof_string... # verify the proof string ```
I've never really shared these tools before, I just remembered about it today. Enjoy!
Try it out: https://github.com/jb55/ots-tools