How to check that nothing has been touched

Svingerud promises that sentences are never edited or deleted. A promise is worth nothing if you have to believe it: this is how to check it without trusting us.

Each sentence is chained to the previous one. Its hash is computed from its number, its text, its publication date and the hash of the preceding sentence. Changing a single letter of an old sentence would change its hash and that of every sentence after it, and that would be visible at once. The first sentence is chained to a hash of zeros.

hash(n) = SHA-256(
  number + "\n" +
  text + "\n" +
  published_at + "\n" +
  prev_hash(n)
)
prev_hash(1) = 0000000000000000000000000000000000000000000000000000000000000000
prev_hash(n) = hash(n-1)

Current tip of the chain

No sentence has been chained yet.

Daily seals

Once a day, the hash of the last sentence — which by construction contains every earlier one — is sealed in OpenTimestamps, which anchors it in the public Bitcoin chain. We do not control that registry and cannot alter it. Download the seal for any day and check it with the official client:

pip install opentimestamps-client
curl -O https://svingerud.com/verificar/2026-08-27.ots
ots verify --digest <hash_de_la_punta> 2026-08-27.ots

No sentence has been chained yet.

Archive

The complete archive can be downloaded at any time, with the hash of each sentence included, and recomputed in full on your own: JSON · TXT · cadena.json

What this proves and what it does not. It proves that a piece of content existed before a particular moment and has not changed since. It does not prove who wrote it. And whether the archive is still available in thirty years does not depend on cryptography, but on copies existing: that is why the whole archive can be downloaded and replicated freely.