Checkpoints of week 2026-W39

21 September 2026 – 27 September 2026 (UTC) · 3 checkpoints

A checkpoint is a signed state of the Merkle tree over the whole Sigelith proof log, chained to the previous checkpoint by the SHA-256 of its file. This page shows the exact bytes of every checkpoint issued in this week, so even a copy of it is enough to recompute each hash.

Weekly checkpoint

This week is not closed yet. Its weekly checkpoint is issued automatically right after Monday 00:00 UTC.

All checkpoints of this week

Checkpoint #1 is the first one ever issued. It covers every entry since the log began on 15 June 2026; the weeks before it are sealed by their own signed weekly roots, OpenTimestamps proofs and bank transfers (proof page).

Anchors and independent copies

Every checkpoint is sealed by parties that depend neither on each other nor on us.

Ed25519 signature

Every file is signed. Check the key against the key history.

Bitcoin block in the file

Not earlier than. Each checkpoint names a Bitcoin block on which two independent sources agree, so it cannot have been written before that block was mined.

OpenTimestamps

Not later than. The SHA-256 of every file is committed to Bitcoin: 3 of 3 proofs of this week already in a block.

Bank transfer

Each weekly Merkle root is anchored by a bank transfer titled MROOT with the root; every weekly checkpoint records the transfers booked since the previous one. All bank anchors.

GitHub

An immutable release 2026-W39 in DeiFlagellum/sigelith-log, published once the week's OpenTimestamps proofs reach Bitcoin.

Internet Archive

A snapshot of this page and of the weekly checkpoint file is saved in the Internet Archive after the GitHub release.

Zenodo

Every quarter a complete snapshot of the log — every checkpoint and every weekly dump — is deposited in Zenodo (CERN) with a permanent DOI.

Public log

Every entry can be downloaded (entries, weekly dumps), so anyone can recompute every root and check every signature.

How to verify

1. Take the checkpoint file from an independent copy, not from us.
2. Check the Ed25519 signature: the message is beattime-checkpoint-v1| followed by the file's JSON without sig, in canonical form (RFC 8785); the key is in key. The format identifier keeps the log's original name — see the naming history.
3. Check the chain: the SHA-256 of each file equals prev of the next one.
4. Check the time: ots verify 000001.json.ots — Bitcoin attests that the file existed.
5. Download the log (entries or weekly dumps) and recompute root over the first tree_size entries (RFC 9162 Merkle tree).

Exact formats and the full procedure: README of DeiFlagellum/sigelith-log and the proof specification.

Exact files

000001.json

{"btc":{"hash":"00000000000000000000e60c66899c2162db615df65ee678c20c834162194e41","height":968542},"format":"beattime-checkpoint-v1","key":"e7y9THJIUKvNKOZHmdBjJ8E0bOKyBFVxxMpAJ8w574Y=","kind":"daily","last_chain_hash":"2b7de591a11151b396097701714f6d84cd4b71e714bb68cfd03b7b3726621090","last_seq":171,"n":1,"prev":null,"root":"d201ae00c834041d29a674358e442481a37ab6f01719e89012180fa44c39a25d","sig":"Zl/g+5RXdjgbbnS53IzcTiHxOEwJQjJk0rh2eppV8psA8Bf959/fPlioa7ouoDvzvjyn0NKqaaHGos6RXN2mAA==","tree_size":171,"utc":"2026-09-25T12:09:44.220276Z"}

000002.json

{"btc":{"hash":"0000000000000000000206860322d9b29efdc0a5ea0a4ff8291d3c4e8a3bbce2","height":968602},"format":"beattime-checkpoint-v1","key":"e7y9THJIUKvNKOZHmdBjJ8E0bOKyBFVxxMpAJ8w574Y=","kind":"daily","last_chain_hash":"373e27d69c849b4fb43a6fdf073facd48c85e4089bfb1b4ae4fdc4a0aa6b0651","last_seq":173,"n":2,"prev":"31db020f471ba267a4538ed31a8f7f10e12b9c4d15832dc5e4594997308e164c","root":"4af8444c8c8c445c6e2347b6d163f542c66d24cba1dbdc1d7e46aae4d761aa7d","sig":"SN2JYNlvhtD/KVhjMEPaqBiSZSalaHen2Hk9pVQ8+Tk/JvDF0Sq6b62DfoY2jMC+vqWtji8GuPJ0rRRNIiKwAA==","tree_size":173,"utc":"2026-09-26T00:09:50.592588Z"}

000003.json

{"btc":{"hash":"00000000000000000000cc3454148dd4af5d3ac25f346443b988bb797c271846","height":968756},"format":"beattime-checkpoint-v1","key":"e7y9THJIUKvNKOZHmdBjJ8E0bOKyBFVxxMpAJ8w574Y=","kind":"daily","last_chain_hash":"8b780ace12f88e1c0e4255d870089a6384cc7bca4a34af1421ec36c79bae7933","last_seq":176,"n":3,"prev":"40013dc859c40b38267c12552e82f9f736549416b8e99159c2673b1bfb52e154","root":"ef8861111817fb4c575ca39f3eceb486c52f7834327b4416df55095c2a23516f","sig":"C2YeU6IctuE2aBGTYKJE5tgTEy8XxjKqd3AQCrTapu5hNZE2NSOe1H1yqikPW4Nc0zXlcPXkgDeB34GPFmeZAA==","tree_size":176,"utc":"2026-09-27T00:09:50.714383Z"}

All weeks