Where were people's favourite lectures?

I attended 7 talks.

My favourite talk by far was hacking the GPG. Brilliant, really: https://media.ccc.de/v/39c3-to-sign-or-not-to-sign-practical...

The "In-house electronics manufacturing from scratch" was a very inspiring talk: https://media.ccc.de/v/39c3-in-house-electronics-manufacturi...

The rest were less good for me personally. Either over-dramatic and shallow (with a sexy-sounding topic) or too procedural in topics I'm not an expert in.

Somehow it did not get much attention, but Signal president Meredith Whittaker (together with Udbhav Tiwari) spoke about the risks and threats from AI-enabled systems.

AI Agent, AI Spy

https://media.ccc.de/v/39c3-ai-agent-ai-spy

I also found the talk about Asahi interesting, both from a technical standpoint but also as a nice update what the current status is.

Asahi Linux - Porting Linux to Apple Silicon

https://media.ccc.de/v/39c3-asahi-linux-porting-linux-to-app...

Finally, not recorded, but workshops like

Foundation workshop: Hands-on, how does the Internet work?

by Ingo Blechschmidt, is congress at its best. Getting a diverse set of people with various backgrounds and knowledge levels to ARP spoof in a little over an hour is art.

https://events.ccc.de/congress/2025/hub/event/detail/foundat...

I also enjoyed the GPG talk. Other highlights:

Not an Impasse: Child Safety, Privacy, and Healing Together: https://media.ccc.de/v/39c3-not-an-impasse-child-safety-priv...

APT Down and the mystery of the burning data centers: https://media.ccc.de/v/39c3-apt-down-and-the-mystery-of-the-...

Bluetooth Headphone Jacking: A Key to Your Phone: https://media.ccc.de/v/39c3-bluetooth-headphone-jacking-a-ke...

"Liberation of the Freebox", A slightly crazy Frenchman embarks on a quest to find exploit and write a complex exploit chain, using PrDoom and the Linux HFS+ driver to gain root privileges on his set-top box. All this in order to unlock the recording of somewhat rubbish TV channels such as TF1 and M6.

And he waited almost ten years and the retirement of the hardware to reveal it because he didn't want it to be patched.

If you are into hardware emulation "From silicon to Darude sand-storm" is fun.

the https://media.ccc.de/v/39c3-from-silicon-to-darude-sand-stor...

order by personal rank:

Sandstorm JP-8000 sawtooth DSP reversing https://www.youtube.com/watch?v=XM_q5T7wTpQ

Washing machines hacking https://www.youtube.com/watch?v=Q1S-PVo3GlA

AMD (ps5 sorta) security: https://www.youtube.com/watch?v=cVJZYT8kYsI

cool demo for the BT headphones talk: https://www.youtube.com/watch?v=TK5Tz4Bt94Y

precise time syncing with PTP: https://www.youtube.com/watch?v=dOt-zRIG5co

x86 > arm with intermediate: https://www.youtube.com/watch?v=3yDXyW1WERg

Absolutely Cory Doctorow's, for the showmanship alone. Lovely background slides. The message itself might not resonate with everyone.

The talk "Look Up" about unencrypted data over DVB satellite links was also though provoking, both in presentation and in technical content. If there's that much data unencrypted over a mainstream IP link, imagine how much is still on legacy protocols in 2025.

I still have to go through my watch list, the age old issue of not having my slides done before congress...

The 10 year of Dieselgate is interesting just from a "how bad is it really?" PoV, I saw the part about curves and other defeat devices already [1].

The Rowhammer talk is likely going to be great as well, I like Daniel's work [2].

The practical Cross-VM Spectre was interesting to show this is still a problem [3].

The opensource secure element was good for trying such a thing, but I wasn't that impressed with the content [4].

[1] https://cfp.cccv.de/39c3/talk/7MSRA7/ https://media.ccc.de/v/39c3-10-years-of-dieselgate

[2] https://cfp.cccv.de/39c3/talk/3JXAJJ/ https://media.ccc.de/v/39c3-rowhammer-in-the-wild-large-scal...

[3] https://cfp.cccv.de/39c3/talk/ATYLN9/ https://media.ccc.de/v/39c3-spectre-in-the-real-world-leakin...

[4] https://cfp.cccv.de/39c3/talk/9DYZXG/ https://media.ccc.de/v/39c3-lessons-from-building-an-open-ar...

Just for sheer geekery's sake probably the ISDN talk.

For OMG eye opening factor the FreeBSD jails talk (how the hell is this thing still so buggy?) and the talk on unencrypted satellite links

For excellent follow-along value and dedication to ridiculously pointless cause the Freebox talk. "Technically I don't own this box so instead of risking damaging it I'm going to take the extremely long and entertaining route around, somehow involving Doom WAD files"

For showmanship probably the Tegra talk

The biggest problem with ccc is that: 0. They are releasing too few tickets. 1. They are releasing the tickets too late. 3. Still not able to pay with card?

I live somewhat nearby, but can’t book or plan a visit because of this. I appreciate that they are releasing videos shortly afterwards though.

https://media.ccc.de/v/39c3-css-clicker-training-making-game... The CSS clicker talk was really entertaining as well as just technological amazing!

The Last of Us - Fighting the EU Surveillance Law Apocalypse

https://media.ccc.de/v/39c3-the-last-of-us-fighting-the-eu-s...

I think the blue team ctf ai talk was a good benchmark were we at right now https://media.ccc.de/v/39c3-breaking-bots-cheating-at-blue-t...

Demystifying Fuzzer Behaviour

https://m.youtube.com/watch?v=h3UcecN5fvQ

The one on the bluetooth headphone vulnerabilities was quite fun: https://media.ccc.de/v/39c3-bluetooth-headphone-jacking-a-ke...

That in-house electronics one is gold.

The one on bsd jails https://media.ccc.de/v/39c3-escaping-containment-a-security-...

The one on whatsapp bugs https://media.ccc.de/v/39c3-dngerouslink-a-deep-dive-into-wh...