hackertube.io

David Kriesel: Traue keinem Scan, den du nicht selbst gefälscht hast

media.ccc.de · talk · Watch on YouTube

Security & hackingInformation theory & signal processingTesting, debugging & developer tools

What it is

David Kriesel's 31C3 talk, in German, on the discovery that Xerox scanner-copiers silently replace digits and letters in scanned documents. He explains how the bug stayed unnoticed in the wild for years.

Why Hacker News recommends it

Called a classic CCC talk, and the Xerox bug is cited as a cautionary tale about trusting scans and digitized archives.

  • 4 people recommended it
  • 5 different months
  • 3 strong recommendations
  • first 2019, last 2025

What HN commenters said

  1. “I would also highly recommend”

    German talk on scanners silently altering documents.

    snicksnak, 2020-12 · Strong recommendation · in “RC3 talk: How to survive in spacecraft [video]”

  2. “If you speak german and haven’t seen this yet, watch it, this is a classic.”

    Legendary CCC presentation on the Xerox scanner number-changing bug.

    solarkraft, 2021-11 · Strong recommendation · in “Confused Xerox copiers rewrite scanned documents, expert finds (2013)”

  3. “Epic talk (in German, David Kriesel,”

    German talk about not trusting scans.

    masswerk, 2022-12 · Strong recommendation · in “Enhance Speech from Adobe – Free AI filter for cleaning up spoken audio”

  4. “It was a really great talk.”

    German talk on scanners replacing digits through pattern matching.

    sdoering, 2021-08 · Recommendation · in “Contract by Email”

Excerpts from Hacker News comments, linked to the originals. Summaries and labels were written by a language model from those comments.

Topics: xerox, jbig2, document scanning, software bugs, ccc

Also recommended by the same people