posts
What do others use for ensuring the authenticity of images after downloading them with docker pull?
We’ve setup our CI build process to use docker for consistent, cross-platform builds. To ensure that our builds don’t use a malicious docker image (because the surface area of attack with TLS is enormous if you’re using X.509), we’ve been using DCT (Docker Content Trust).
Unfortunately, I just discovered that the official docker documentation says that DCT is being deprecated. Apparently this was announced last year, and in June this blog post was published with advice:
Cosign is not secure
We spent some time looking into cosign, but we discovered that the private keys aren't actually in the hands of the developer.
Rather, they use this complicated setup using very insecure X.509 to issue temporary certificates.
The result is that the OIDC identity provider (e.g., GitHub) extends the vector of attack significantly -- to probably tens of thousands of people -- that can publish a malicious image that will be accepted by cosign as "trusted"
Notation (Notary v2)
I also looked at Notation (aka “Notary v2”), but there’s no way to bootstrap the software safely, since (perplexingly) their tool for verifying the authenticity of images using cryptographic signatures itself can’t be verified using a cryptographic signature.
Alternatives
Are there any other alternatives that I can use to replace DCT to ensure the authenticity (using cryptography) of the container images that I download -- where the keys are actually held by the developer (thus significantly reducing the "insider threat" risk)?
What do you (or does your org do) to ensure that you’re not using maliciously-modified containers after pulling a new docker image?
How to manage controlled burning of paper either inside or in a backyard where fires may or may not be legal. I am not endorsing or personally considering these actions in any inappropriate setting.
We're thrilled to announce that BusKill was the recipient of a $1,031 microgrant from FUTO!
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| Can't see video above? Watch it on PeerTube or on YouTube at youtu.be/Qr0VusrG1jE |
We're elated to see BusKill join the ranks next to CryptPad, ExifTool, KeePassXC, Whonix, Wireshark, Tor Project, Calyx, and numerous other awesome projects that have received grants from FUTO.
Iterate with us!
Want to print your own BusKill cable? We'll cover your expenses for filament, magnets, and pogo pins.
We plan to use these funds to document our 3D-Printable BusKill Dead Man Switch. And we need your help!
The BusKill project is looking for a volunteer to write the documentation describing how to print and build your own BusKill cable. The documentation will be written for our Sphinx Documentation Site in reStructuredText and pushed in git.
If you have access to a 3D-Printer, please contact us to receive funds to buy the components needed to document the build of a 3D-Printed BusKill.
What is BusKill?
BusKill is a laptop kill-cord. It's a USB cable with a magnetic breakaway that you attach to your body and connect to your computer.
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| Watch the BusKill Explainer Video for more info on PeerTube or youtube.com/v/qPwyoD_cQR4 |
If the connection between you to your computer is severed, then your device will lock, shutdown, or shred its encryption keys -- thus keeping your encrypted data safe from thieves that steal your device.
Support BusKill
We're looking forward to continuing to improve the BusKill software and looking for other avenues to distribute our hardware BusKill cable to make it more accessible this year.
If you want to help, please consider purchasing a BusKill cable for yourself or a loved one. It helps us fund further development, and you get your own BusKill cable to keep you or your loved ones safe.
Buy a BusKill Cable
https://buskill.in/buy
You can also buy a BusKill cable with bitcoin, monero, and other altcoins from our BusKill Store's .onion site.
Stay safe,
The BusKill Team
https://www.buskill.in/
http://www.buskillvampfih2iucxhit3qp36i2zzql3u6pmkeafvlxs3tlmot5yad.onion/
This post contains a canary message that's cryptographically signed by the official BusKill PGP release key
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| The BusKill project just published their Warrant Canary #010 |
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
Status: All good
Release: 2025-06-16
Period: 2025-06-01 to 2026-05-31
Expiry: 2026-06-30
Statements
==========
The BusKill Team who have digitally signed this file [1]
state the following:
1. The date of issue of this canary is July 16, 2025.
2. The current BusKill Signing Key (2020.07) is
E0AF FF57 DC00 FBE0 5635 8761 4AE2 1E19 36CE 786A
3. We positively confirm, to the best of our knowledge, that the
integrity of our systems are sound: all our infrastructure is in our
control, we have not been compromised or suffered a data breach, we
have not disclosed any private keys, we have not introduced any
backdoors, and we have not been forced to modify our system to allow
access or information leakage to a third party in any way.
4. We plan to publish the next of these canary statements before the
Expiry date listed above. Special note should be taken if no new
canary is published by that time or if the list of statements changes
without plausible explanation.
Special announcements
=====================
1. We are changing from twice-yearly to once-yearly canaries
Disclaimers and notes
=====================
This canary scheme is not infallible. Although signing the
declaration makes it very difficult for a third party to produce
arbitrary declarations, it does not prevent them from using force or
other means, like blackmail or compromising the signers' laptops, to
coerce us to produce false declarations.
The news feeds quoted below (Proof of freshness) serves to
demonstrate that this canary could not have been created prior to the
date stated. It shows that a series of canaries was not created in
advance.
This declaration is merely a best effort and is provided without any
guarantee or warranty. It is not legally binding in any way to
anybody. None of the signers should be ever held legally responsible
for any of the statements made here.
Proof of freshness
==================
16 Jun 25 19:17:39 UTC
Source: DER SPIEGEL - International (https://www.spiegel.de/international/index.rss)
"Teacher Li": Catching Up with the Most Effective Chinese Regime Opponent
Firing at the Desperate: Palestinians Killed as They Gather to Receive Relief Supplies
Source: NYT > World News (https://rss.nytimes.com/services/xml/rss/nyt/World.xml)
Live Updates: Israel Strikes Iranian State TV as It Expands Targets in Tehran
With No Clear Off-Ramp, Israel’s War With Iran May Last Weeks, Not Days
Source: BBC News - World (https://feeds.bbci.co.uk/news/world/rss.xml)
No further damage seen at Iran nuclear sites, global watchdog says
'Nowhere feels safe': Iranians on life under Israeli attacks
Source: Bitcoin Blockchain (https://blockchain.info/q/latesthash)
00000000000000000000f2c3a15949aac2f6d7bc153330a4fca496f68c8c4b21
Footnotes
=========
[1] https://docs.buskill.in/buskill-app/en/stable/security/pgpkeys.html
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Sa4k/6pswal3CYJSu+imbRmhoFnpv1pFZ1ch2b8k8K/1q727NkU=
=1XvB
-----END PGP SIGNATURE-----
What is a Warrant Canary?
The BusKill team publishes cryptographically signed warrant canaries on an annual basis.
Although security is one of our top priorities, we might not be able to inform you of of a breach if served with a State-issued, secret subpoena (gag order).
The purpose of publishing these canary statements is to indicate to our users the integrity of our systems.
For more information about BusKill canaries, see:
To view all past canaries, see:
What is BusKill?
BusKill is a laptop kill-cord. It's a USB cable with a magnetic breakaway that you attach to your body and connect to your computer.
![]() |
|---|
| Watch the BusKill Explainer Video for more info youtube.com/v/qPwyoD_cQR4 |
If the connection between you to your computer is severed, then your device will lock, shutdown, or shred its encryption keys -- thus keeping your encrypted data safe from thieves that steal your device.




