https://peertube.nextcloud.com/videos/watch/e34609a8-8d66-4a86-8966-79ef9fcf2728 We welcome everyone to watch the recordings of the lightning talks from the Nextcloud Community Conference 2026! About this lightning talk: Speaker: Jonna Fassbender Title: Verifying that a file existed, without asking the server that stored it Description provided by the author: If you self-host, you can show that a file was in your instance at a given moment. But the party producing that evidence is also the party that controls it. For most purposes that is fine. For the cases where it is not, the evidence has to be checkable somewhere you do not run. This lightning talk demonstrates one way to close that gap, using a hash committed to the Bitcoin blockchain so that anyone can replay the proof against a block header. Live demo, four public test vectors, no call to any vendor. What are lightning talks? Lightning talks are quick presentations from the Nextcloud community about contributing, developing Nextcloud apps, privacy and data sovereignty, and more. We have recorded the lightning talks during the event so everyone who couldn’t make it to the event can watch these inspiring sessions. ⚠️ Note: this is a live recording of a session from an in-person event. Audio and video quality may differ from our studio content. More about the event: https://nextcloud.com/conference-2026/ Thu, 15 Oct 2026 04:44:25 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://peertube.nextcloud.com https://peertube.nextcloud.com/lazy-static/avatars/b63dde0a-7d1d-47e6-95e8-637d4df6ade2.png https://peertube.nextcloud.com/videos/watch/e34609a8-8d66-4a86-8966-79ef9fcf2728 All rights reserved, unless otherwise specified in the terms specified at https://peertube.nextcloud.com/about and potential licenses granted by each content's rightholder.