Matthew Green
@matthewdgreen.bsky.social
📤 18529
📥 406
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I teach cryptography at Johns Hopkins.
https://blog.cryptographyengineering.com
reposted by
Matthew Green
hikikomorphism
2 days ago
I have a long-running Claude session just for talking about Iran war news/economic shocks from the blockade. I shared the latest Trump tweet and it told me that it can no longer keep role-playing this fictional scenario because it's becoming concerning and detached from reality. Love this timeline.
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Everything on crypto Twitter/X is quantum computing hype. It’s amazing how obviously artificial this all is.
2 days ago
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reposted by
Matthew Green
Filippo Valsorda
4 days ago
Alright, it's official! đź’°
@matthewdgreen.bsky.social
and I bet on what will break first, ML-KEM-768 or X25519. The loser donates to a 501(c)(3) picked by the winner. If you have an opinion on quantum computers or lattices, you can join with a side bet. Just submit a PR!
github.com/FiloSottile/...
add a skeleton here at some point
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reposted by
Matthew Green
Zack Whittaker
4 days ago
New: France said it plans to move its government computers currently running Windows to the open-source software Linux to further reduce its reliance on U.S. tech. Comes at a time of growing instability and unpredictability on the part of the Trump administration and weaponization of sanctions, etc.
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France to ditch Windows for Linux to reduce reliance on US tech | TechCrunch
France's move to ditch Windows for Linux is its latest effort to reduce its reliance on American tech giants.
https://techcrunch.com/2026/04/10/france-to-ditch-windows-for-linux-to-reduce-reliance-on-us-tech/
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reposted by
Matthew Green
Nigel Smart
5 days ago
Betting on the Quantum Apocalypse...
www.theregister.com/2026/04/09/c...
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https://www.theregister.com/2026/04/09/cryptograhpers_quantum_bet/
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reposted by
Matthew Green
Zack Whittaker
6 days ago
New, by me at TechCrunch: The developer of the widely popular Wireguard VPN says he is also unable to ship software updates to Windows users after Microsoft locked his account, marking the second high-profile app developer (VeraCrypt) in the past few weeks to face this issue.
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WireGuard VPN developer can't ship software updates after Microsoft locks account | TechCrunch
The popular open source VPN maker is the second high-profile developer to say Microsoft locked his account without notifying him and are blocking their ability to send software updates to users.
https://techcrunch.com/2026/04/08/wireguard-vpn-developer-cant-ship-software-updates-after-microsoft-locks-account/
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We should be able to slow down AI takeover by a few years just by telling the model to find every bug in ffmpeg.
7 days ago
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reposted by
Matthew Green
Paul Frazee
7 days ago
I feel like we're not addressing the most concerning news from Mythos
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reposted by
Matthew Green
Juliet Shen
8 days ago
this is honestly THE best write up of how CSAM detection and perceptual handing works. the visual aids are very helpful in understanding how content is transformed and how detection methods work
mahmoud-salem.net/the-invisibl...
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How Do You Find an Illegal Image Without Looking at It?
61.8 million files of suspected child abuse were reported in 2025 alone. This is how machines detect them at internet scale — without any human ever seeing the content.
https://mahmoud-salem.net/the-invisible-shield
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I think this is a good precautionary analysis but I’d bet huge amounts of money against a relevant quantum computer by 2029 or even 2035.
add a skeleton here at some point
8 days ago
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Does anyone over here know anything about which stablecoins Iran might be using to demand tolls for Hormuz transit?
www.bloomberg.com/news/article...
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Secret Codes and Yuan Fees Get Ships Through Iran’s Hormuz Tollbooth
Vessels wanting to transit the strategic waterway need to be from friendly countries, and some have to pay fees in Chinese currency or crypto before being escorted through the strait.
https://www.bloomberg.com/news/articles/2026-04-01/strait-of-hormuz-ships-paying-iran-yuan-and-crypto-tolls-for-safe-passage?embedded-checkout=true
8 days ago
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Well, at least blockchains are getting exciting again.
9 days ago
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reposted by
Matthew Green
Natanael, Tech janitor
9 days ago
gizmodo.com/group-pushin...
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Group Pushing Age Verification Requirements for AI Turns Out to Be Sneakily Backed by OpenAI
It gave the leader of a nonprofit involved with it
https://gizmodo.com/group-pushing-age-verification-requirements-for-ai-turns-out-to-be-sneakily-backed-by-openai-2000741069
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My weekend hobby project this week was to Claude Code a GPS-based text adventure game. It takes your local neighborhood and builds a fantasy story, Zork style, around real locations. Uses text-to-speech and live AI storytelling.
9 days ago
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reposted by
Matthew Green
James Ball
11 days ago
I tend to get dogpiled every time I say this but: as someone *who likes bluesky and benefits from being here* we have a problem. The network is shrinking, not growing. It's shrinking a lot: only about 1.1m people a day even like a post. This time last year it was 1.6m.
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This is a great article on vulnerability research in the (coming) age of AI, by Thomas Ptacek. It mostly focuses on the fact that machines will soon supplant human vulnerability researchers. That’s sad! But my question is: do we get safer, or do we get less safe?
sockpuppet.org/blog/2026/03...
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Vulnerability Research Is Cooked
https://sockpuppet.org/blog/2026/03/30/vulnerability-research-is-cooked/
14 days ago
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Neat paper on securing cryptocurrencies against quantum attacks. I want to stress that I am not convinced we have anything to worry about in my lifetime. This tweet might haunt me.
quantumai.google/static/site-...
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https://quantumai.google/static/site-assets/downloads/cryptocurrency-whitepaper.pdf
14 days ago
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reposted by
Matthew Green
Eric Rescorla
17 days ago
This week on the newsletter: "How not to mandate device-based age assurance"
educatedguesswork.org/posts/device...
In this post, we examine a number of enacted or proposed requirements for device-based age assurance and some of the ways they can go wrong.
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How not to mandate device-based age assurance
Software design by legal mandate
https://educatedguesswork.org/posts/device-based-age-assurance/
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I’m really just trying to remember what this reminder was supposed to tell me.
17 days ago
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You can blow up your opponents by shooting their shields with an unmanned laser, and instead you’re fighting them with knives?
18 days ago
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I understand that every business has decided not to answer the phone anymore, and that would be ok if you could reach them through their apps or websites or even “AI” but of course you can’t.
18 days ago
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Ask Claude about the string “ba7816bf8f01cfea414140de5dae2ec73b00361bbef0469f11ef0b01d449c8e6”. When it gives you an answer: ask it to verify that this number is correct.
19 days ago
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Lawmakers are pressing Tulsi Gabbard to reveal whether use of a VPN (foreign or even in the US) may expose you to surveillance by the NSA.
www.wired.com/story/using-...
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Using a VPN May Subject You to NSA Spying
US lawmakers are pressing Tulsi Gabbard to reveal whether using a VPN that connects to overseas servers can strip Americans of their constitutional protections against warrantless surveillance.
https://www.wired.com/story/using-a-vpn-may-subject-you-to-nsa-spying/
19 days ago
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Got this at a concert. What a neat little device.
20 days ago
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I want to continue a bit on this subject, which (so far) I see very little concern about. There are vast stores of private data that we’ve built up in various places, including messaging apps. A real “killer app” for Gen AI is to ingest them and turn that data into revenue.
23 days ago
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reposted by
Matthew Green
The user is going to download WhatsApp and get whatever defaults or “strongly recommended and nudged” opt-ins they get. And security folks who know better will say things like “the user chose a threat model” while five years of backed-up data goes into the ingestion pipeline.
24 days ago
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Here’s a good article about Meta’s very frustrating decision to pull encryption out of Instagram.
www.wired.com/story/the-da...
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The Danger Behind Meta Killing End-to-End Encryption for Instagram DMs
Meta blamed users for not opting into the privacy-protecting feature. Experts fear the move could be the first major domino to fall for end-to-end encryption tech worldwide.
https://www.wired.com/story/the-danger-behind-metas-decision-to-kill-end-to-end-encrypted-instagram-dms/
24 days ago
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reposted by
Matthew Green
Alec Muffett
25 days ago
This is absolute perfection: UBUNTU SECURE BOOT AGE VERIFICATION | Hacker.House
https://alecmuffett.com/article/150554
#AgeVerification
#OnlineSafetyAct
#OpenSource
#censorship
#kosa
#systemd
#ubuntu
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This is absolute perfection: UBUNTU SECURE BOOT AGE VERIFICATION | Hacker.House
Perfect commentary on nerds following authoritarianism because it is an interesting intellectual challenge:
https://alecmuffett.com/article/150554
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Dachshunds, like humans, sometimes need reading glasses as they age.
25 days ago
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Using Tor in 2026.
25 days ago
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Things are going well with Google AI.
26 days ago
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So you’re going all in on AI, presumably AI that makes software development cost close to nothing. But also: you’re canceling major software development initiatives that should now cost you close to zero.
www.theverge.com/tech/863209/...
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Meta has discontinued its metaverse for work, too
One more piece of bad news for VR.
https://www.theverge.com/tech/863209/meta-has-discontinued-its-metaverse-for-work-too
27 days ago
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I’ve spent the last two days coding up a simulator for Meshcore using Claude Code, and it’s frankly amazing to be able to do this.
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28 days ago
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We are absolutely rewriting grants, because using the word “censorship” (as in “censorship-resistant networking that allows people in Iran to bypass filters and access the Internet) gets your grants cancelled by the idiots at DOGE.
add a skeleton here at some point
29 days ago
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This is the decade of stupid people finally getting their wish and having the chance to run the world their way.
30 days ago
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Meta appears to be reversing its strong stance on encryption. The first obvious casualty is that they’re abandoning and disabling end-to-end encryption in Instagram DMs.
about 1 month ago
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reposted by
Matthew Green
ChrisO_wiki
about 1 month ago
2/ The forthcoming ban on Telegram – likely to be announced on 1 April – appears to have woken up many Russian bloggers to the way the Russian government is systematically attacking free speech. 'Under the ice' predicts catastrophe:
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The EU seems to be going in the right direction when it comes to mass message scanning. Unfortunately, the fact that this vote was necessary proves that we’re still in the dark timeline.
cyberinsider.com/eu-votes-to-...
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EU votes to restrict mass scanning of people’s private messages
The European Parliament has voted to curb untargeted mass scanning of private communications in the EU, in a key 'Chat Control' development.
https://cyberinsider.com/eu-votes-to-restrict-mass-scanning-of-peoples-private-messages/
about 1 month ago
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reposted by
Matthew Green
David Ho
about 1 month ago
The 2026 National Science Foundation budget is $8.75 Billion.
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First 6 Days of Iran War Cost U.S. $11.3 Billion, Pentagon Says
https://www.nytimes.com/live/2026/03/11/world/iran-war-news-trump-oil-israel?unlocked_article_code=1.SlA.vTQm.rWeA0T_H9N7Y&smid=url-share
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Such an oddly specific number.
www.theregister.com/2026/03/11/s...
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Swiss e-vote snafu leaves 2,048 ballots unreadable
: Officials suspend Basel-Stadt trial and launch probe
https://www.theregister.com/2026/03/11/swiss_evote_usb_snafu/
about 1 month ago
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I don’t think online conservatives have figured out how badly they’re about to be crushed electorally. That’s the downside of living inside those bubbles on X and Substack.
about 1 month ago
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Numbers stations are back! Um.
open.substack.com/pub/theicema...
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A New Spy Radio Signal Has Appeared. It's Broadcasting in Farsi.
A new shortwave numbers station appeared the day the bombs fell. Nobody knows who's running it.
https://open.substack.com/pub/theiceman/p/a-new-spy-radio-signal-has-appeared?r=4513r&utm_medium=ios
about 1 month ago
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reposted by
Matthew Green
Filippo Valsorda
about 1 month ago
Dustin Moody from NIST: “you don’t need more than 128 bits of symmetric keys for post-quantum security”
#rwc2026
Say it louder, for the people in the back!
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If you make an account using “Sign in with Google”, how many websites will let you access that same account through “Sign in with Apple” (or vice versa) if the email address is the same? Is that considered the expected behavior?
about 1 month ago
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reposted by
Matthew Green
The Register
about 1 month ago
'Hundreds' of Iranian hacking attempts have hit surveillance cameras since the missile strikes
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'Hundreds' of Iranian hacking attempts have hit surveillance cameras since the missile strikes
Attack infrastructure attributed to 'several Iran-nexus threat actors' Multiple Iranian hacking crews have been targeting internet-connected surveillance cameras across Israel and other Middle Eastern countries since the war started on February 28, according to Check Point security researchers. …
http://dlvr.it/TRJCLF
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TikTok announces that they’re not going to deploy “controversial privacy tech” that’s actually the same end-to-end encryption most other providers use to protect users’ DMs.
www.bbc.com/news/article...
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TikTok says it won't encrypt DMs claiming it puts users at risk
TikTok tells the BBC it won't join rival platforms such as WhatsApp and Messenger in using end-to-end encryption.
https://www.bbc.com/news/articles/cly2m5e5ke4o
about 1 month ago
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Senators Wyden and Brown are requesting an investigation into side-channel and TEMPEST attacks.
www.wired.com/story/how-vu...
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How Vulnerable Are Computers to an 80-Year-Old Spy Technique? Congress Wants Answers
A pair of US lawmakers are calling for an investigation into how easily spies can steal information based on devices’ electromagnetic and acoustic leaks—a spying trick the NSA once codenamed TEMPEST.
https://www.wired.com/story/how-vulnerable-are-computers-to-an-80-year-old-spy-technique-congress-wants-answers/
about 1 month ago
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I wrote a new post on anonymous credentials and how to build them. All of this is in service on a longer future post on how these will fit into age verification systems.
blog.cryptographyengineering.com/2026/03/02/a...
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Anonymous credentials: an illustrated primer
This post has been on my back burner for well over a year. It’s been sitting here unwritten, not because the topic is unimportant — in fact, with every single month that goes by, I become mor…
https://blog.cryptographyengineering.com/2026/03/02/anonymous-credentials-an-illustrated-primer/
about 1 month ago
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I know it’s going to be hard to believe, but this was an impulse purchase.
about 1 month ago
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I heard an interesting anecdote about TEEs from some folks in fintech. They were trying to convince regulators that TEEs aren’t just “computers under their control”, so they tried to get cloud providers to certify that they would never hand over the keys to a client. Providers could not do this.
add a skeleton here at some point
about 2 months ago
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