Why we can't cheat — even if we wanted to
A timestamping service is only useful if it can't lie. Instead of asking you to trust our good intentions, KnownSince is built so that manipulation is detectable by anyone. Here is every layer, and how to check each one yourself.
1. We never see your content
Fingerprints are computed in your browser. Our servers receive 64 hex characters and nothing else — there is nothing for us to leak, sell, or alter. You can confirm this in your browser's network inspector while stamping: the only thing sent is the fingerprint.
2. The timestamps aren't ours — they're Bitcoin's
We don't put a date on your proof; the Bitcoin blockchain does. Your fingerprint is anchored via the open OpenTimestamps standard into a Bitcoin block, and block times are set by the global network. Backdating a proof would require rewriting Bitcoin's history — not something we, or anyone, can do.
3. Your proof works without us
Every certificate includes a downloadable receipt that verifies with the official, open-source OpenTimestamps client — no KnownSince servers involved. If we disappeared tomorrow, every proof ever issued would keep working.
4. A public, chained record of everything we do
Every day at 00:05 UTC, we fold all fingerprints stamped that day into a single merkle root and publish it to a public, append-only log on GitHub: magicmountainsoftware/knownsince-transparency.
Each day's entry contains the cryptographic hash of the previous day's entry — a hash chain. That means a single saved copy of today's entry commits to our entire history: if we ever altered or deleted anything from any past day, every entry after it would stop matching, publicly and permanently.
And the chain head doesn't rely on GitHub either: each daily entry's hash is itself stamped through KnownSince and anchored in Bitcoin, with the proof linked from the commit message.
What this adds up to
- We can't read your content — we never receive it.
- We can't backdate a proof — Bitcoin sets the clock, not us.
- We can't quietly delete or rewrite history — the public hash chain breaks visibly.
- We can't lock you in — proofs verify with independent tools, forever.
Trust is good. Not needing it is better.