Nelson LopezMar 24
Matt Blaze

Signal provides:

- Excellent protection against third party interception of communications (wiretapping).

- Limited protection against compromised (hacked) or lost devices

- No protection against certain common usage mistakes (accidentally including a reporter in your large group war planning chat).

Mar 24 at 7:30pmWeb
Show threadMatt BlazeMar 24

If you look at the systems that are supposed to be used for classified communications, the underlying cryptography isn’t particularly different from Signal (the AES cipher can be used to protect classified material). That’s not what failed here.

The difference is that systems like Signal are designed to *facilitate* communication with anyone. Classified systems are designed to *limit* communication to authorized recipients.

Both are sensible for their respective - very different - purposes.

Show threadKuJoe 💞Mar 24
@mattblaze what app do I download that has “Man-in-the-Middle (because I invited him)” protection?
Show threadRaglan Niall  Mar 25
@KuJoe
Maybe with this you can at least see your mistake?
@mattblaze
Show threadTanguy ⧓ HerrmannMar 26
@Niall @KuJoe @mattblaze fav'ed, just for the alt text. 🤣
Show threadRaglan Niall  Mar 26
@dolanor @KuJoe @mattblaze glad someone noticed :-D
Show threadkatzenberger 🇺🇦Mar 24

@mattblaze

Most likely Signal was chosen because a) it helps bypassing documentation requirements, as has been the case with similar cases, and b) it protects against interception.

The more interesting question that nobody has asked so far, despite it's being hinted at in the article in The Atlantic: why is a) so acceptable that all of these folks routinely use Signal for that purpose? You don't "accidentally" tune in to such undocumented conversations.

Show threadPēteris KrišjānisMar 24
@katzenberger @mattblaze a) is applying too much intelligence to these guys
Show threadStryder NotaviMar 25

@peteriskrisjanis @katzenberger @mattblaze Not necessarily - avoiding FOI requests has been a major focus for Project 2025.

Not sure why they're worried about their actions being scrutinized </sarcasm>

Show threadkatzenberger 🇺🇦Mar 25

@peteriskrisjanis

On the contrary, it is deliberate obstruction. Look at the chat screenshots in the article:

https://www.theatlantic.com/politics/archive/2025/03/trump-administration-accidentally-texted-me-its-war-plans/682151/

The messages have the timer icon, bottom right. This means that #DisappearingMessages was enabled for this #Signal chat.

@mattblaze

The Trump Administration Accidentally Texted Me Its War Plans

U.S. national-security leaders included me in a group chat about upcoming military strikes in Yemen. I didn’t think it could be real. Then the bombs started falling.

The Atlantic
Show threadCodexNotFoundMar 26
@katzenberger
The reason why signal is used widely by government officials is to let recipients know they have send something over the secure line. The secure line is something they have at home or in their office so it cannot be lost. @mattblaze
Show threadMatt BlazeMar 26
@CodexNotFound @katzenberger And anyone at or near the cabinet level (as here) has access to secure communications wherever they are (including in transit).
Show threadity [unit X-69]Mar 24

@mattblaze

Infodump follows aimed at nobody in particular:

AES is the symmetric cipher, Signal uses ECC (on Curve25519 & derivatives: So X25519 and Ed25519) for the DR protocol, and ML-KEM as the KEM for the initial key exchange.

ECC is not quantum-safe: You can recover a private key from the public key and decrypt communication if you have a quantum computer. The protection from using a PQC (post-quantum) KEM for the initial key exchange is limited.

Additionally, Signal has a specific threat model, which can make using it insecure for a lot of usecases. For one, it is not anonymous. This means that it does not protect your identity, it only protects your messages. Aka it is fine for chatting with trusted parties, but dangerous for chatting with untrusted parties.

Show threadMatt BlazeMar 24
@ity thank you for the cryptography lesson. I am new to all this stuff.
Show threadGlyphMar 24
@mattblaze thank you matt, this made me laugh out loud
Show threadGlyphMar 24
@mattblaze “fediverse shitposter johnny still can’t PQ encrypt”
Show threadSophie SchmiegMar 25
@glyph @mattblaze that part isn't even accurate, having PQC in the initial key exchange is sufficient in Signal's threat model at this point in time.
Show threadity [unit X-69]Mar 24
(Edit: Yes I googled the name after. I still think it's okay to infodump about cryptography even to someone that knows more cryptography than me.)
Show threadMatt BlazeMar 24
@ity you’re clearly the expert here. Probably too advanced for me to be able to follow.
Show threadity [unit X-69]Mar 24

@mattblaze I am starting to feel like I said something wrong here ?

If there's any mistakes in what I said feel free to correct me, I am always eager to learn ^^

Show threadSteve BellovinMar 24
@ity @mattblaze Hint: look at https://www.mattblaze.org/papers/ — and yes, it's his web page; I've known Matt for >30 years, and he's my modal co-author.
Technical Papers

Show threadVoid TurtleMar 24

@ity

Matt Blaze is a well know academic security expert, so he's poking fun at being lectured on systems he understands very well lol

Show threadity [unit X-69]Mar 24
@void_turtle If what I said came off as lecturing then apologies as that was not my intention, I was moreso infodumping to any interested readers (since this is public social media)
Show threadVoid TurtleMar 24

@ity Additional context you might be missing: He was commenting specifically on this breaking news story wherein top level US government people accidentally added a journalist to their signal loop planning military strikes, so the quantum safety (or lack thereof) of signal and the lack of anonymity is pretty irrelevant to this specific issue. Your post might have come off as lecture-y for this reason

https://www.theatlantic.com/politics/archive/2025/03/trump-administration-accidentally-texted-me-its-war-plans/682151/

The Trump Administration Accidentally Texted Me Its War Plans

U.S. national-security leaders included me in a group chat about upcoming military strikes in Yemen. I didn’t think it could be real. Then the bombs started falling.

The Atlantic
Show threadity [unit X-69]Mar 24

@void_turtle Ah, yea I was missing that context completely :(

I don't keep up with US news anymore, it's too depressing

Show threadblausand 🐟Mar 25
@ity @void_turtle
What an absolutely hilarious way of learning who @mattblaze is 🤣
Show thread0xC0DEC0DE07E9Mar 24
@ity @mattblaze you’re explaining something kinda beside the point to an academic cryptographer who is almost certainly completely aware.
https://www.mattblaze.org/papers/
Technical Papers

Show threadity [unit X-69]Mar 24
@c0dec0dec0de @mattblaze To me it feels important enough to mention that Signal's cryptography is not impenetrable ? Whether whoever I am replying to is aware of it seems besides the point, since those reading his post might not be.
Show threadMatt BlazeMar 24
@ity @c0dec0dec0de I didn’t say it was impenetrable. I don’t know whether it’s impenetrable. I said it wasn’t what failed here, because it wasn’t.
Show threadity [unit X-69]Mar 24

@mattblaze @c0dec0dec0de

Ah, I misread your post then, I was missing the context it was in since I don't follow US news a lot. That's fair ^^

Show threadScissors Cut Paper...Mar 25

@c0dec0dec0de @ity @mattblaze

I thought it was for followers.

And nosy folks like me.

Show threadVarxMar 24

@ity @mattblaze oh no, now I feel bad for the chuckle.

Your first reply came across as correcting or explaining to him directly and @mattblaze is a well regarded cryptography expert and definitely knows all that.

I'm gunna take a swag at how your brain works and just say that I've been there. Even though this is a public forum, when you reply to someone it's generally taken as a direct reply to them unless otherwise specified. So next time just maybe preface with the info dump explanation you gave here.

Don't take it personally, you weren't trying to be rude, you were just excited and it came off in a wrong way.

Show threadity [unit X-69]Mar 24

@varx @mattblaze

Thanks >.< Yea, I was not trying to be rude, and rather just wanted to infodump about cool cryptography things. I can edit the post to make it clearer that an infodump follows ig

Show threadRaph LevienMar 24
@mattblaze @ity Now I feel cheated. Are you saying that the internship I did with you... checks notes... 29 years ago was worth nothing at all?
Show threadAI6YR BenMar 24
@mattblaze LOL this last one seems the most relevant https://xkcd.com/538/
Security

xkcd
Show threadBerndMar 24
@ai6yr @mattblaze otherwise known as "rubberhose cryptanalysis":
https://en.wikipedia.org/wiki/Deniable_encryption#rubber
Deniable encryption - Wikipedia

Show threadSaulMar 24
@hopfgeist @ai6yr @mattblaze Never has the term ‘clusterfuck’ been more appropriate.
Show threadmccMar 24
@ai6yr @mattblaze To be clear, it's slightly more likely that rather than a literal wrench a government entity will simply issue a subpeona for your (or your chat counterparty's) chat logs and threaten jail if you don't comply.
Show threadLisPiMar 24
@mcc @mattblaze @ai6yr It helps when one would get a lot more than just jail if one doesn't comply.

A subpoena would also only apply in cases where one doesn't have a Right to Silence. (The UK is one such nightmare state.)
Show threadmccMar 24

@lispi314 @mattblaze @ai6yr You may have a right to silence, but if the state can credibly charge you with a separate crime, they can induce you to waive that right in exchange for "voluntary" cooperation.

It is the case that the United States appears to be transitioning from government threats backed by legal force to government threats backed by wrenches. I am trying not to say anything alarmist in Mr. Blaze's mentions tho.

Show threadAI6YR BenMar 24
@mcc @lispi314 @mattblaze Yes, unfortunately, the wrenches seem to have come out of their toolboxes (IMHO).
Show threadLisPiMar 24
@mcc @ai6yr @mattblaze I now realized I failed in my original phrasing. Probably rewrote that sentence too many times.

> It helps when one would get a lot more than just jail if one doesn't comply.

If one *does comply* is what I meant.

Of course at some point one has to consider that not getting caught alive might be the modus operandi to go by.
Show threadAndreas KMar 24

@mcc
Sadly we long reached the point where the prosecution process in many cases can be quite punishing already for normal folks, so yes, in many cases intimation it's nowadays called solid police work. Look here, we wouldn't be questioning you if you were innocent. Want us to lock up your whole family in investigative custody? How many of them will lose their jobs and their income?

So tell us how you did, all details please.

@lispi314 @mattblaze @ai6yr

Show threadLisPiMar 25
@yacc143 @ai6yr @mattblaze @mcc In such a situation suicide, possibly by cop, is potentially the only good option.

There is absolutely no reason to trust that they will not harm the family or frame them for other reasons, for the fun of it, anyway.

Collaboration gives nothing. Angering them /might/ increase the chances of such retaliation, but in all likelihood it was going to happen anyway.
Show threadAndreas KMar 25

@lispi314
Ah, you are talking about bad places where people disappear, ...

My comment was more about nice rule of law democracies where law enforcement does also take sometimes a heavy hand approach. Suicide my not be necessary, in that case, but an understanding of the rules of the game would help.
@mattblaze @ai6yr @mcc

Show threadJeremy ListMar 26
@lispi314 @mattblaze @ai6yr @mcc I've heard of a case where someone in the UK got jailed because cops convinced themselves and a judge that a file full of astronomical data was encrypted.
Show threadLisPiMar 26
@jeremy_list @mcc @ai6yr @mattblaze Yup, without a right to silence they can literally just pick random cat pictures on one's computer, claim they're encrypted, and then jail one for failing to decrypt them (while knowing full well the entire time that they never were encrypted).
Show threadGeoff CoffeyMar 24
@mcc @ai6yr @mattblaze I believe it was Thomas Hobbes who said "without the $5 wrench there is no justice."
Show threadKim ScheinbergMar 25

@mcc @ai6yr @mattblaze
If I learned anything from Eric Adams it's that I can change my phone's password, 'forget' what I've changed it to, and wait for half a dozen people to resign before my case gets indefinitely adjourned.

🎶 The one thing we need is a left-handed monkey wrench 🎶

Show threadVissMar 24
@mattblaze this news fits squarely into my 'dipshits gonna dipshit' classifier
Show threadPaul Will Gamble  🇨🇦Mar 24

@mattblaze my fam straight up refused to abandon Whatsapp.

Reason: meh… it’s just easier

My anti-facist rants are falling on complacent ears. So I’m blissfully out of the loop on family discussions and photos. 🤷🏻‍♂️

Show threadRuben Borg NielsenMar 25
@paulywill I’m getting there too. I am not onboard with willingly enabling fascism. If they are; then I have nothing to discuss with them anyways 😡
Show threadPaul Will Gamble  🇨🇦Mar 25
@eldamir I snipped from everything Meta and not going back. My wife is in the creative/performing circles and it’s amazing how many are addicted and actively building their brand and following on Instagram…posting and re-posting thoughts and protest that are ironically the very thing they wish to fight. 🤦‍♂️
Show threadPaul Will Gamble  🇨🇦Mar 25

@mattblaze My sibling did mention a random news article about some RCMP officers getting caught sharing inappropriate material on Signal…but were on a shared network. Thus, Signal must be bad.

I have no doubt there’s active attempts by Meta Inc. (and probably lobbyists) posting misleading and misinformation about Signal and Fediverse alternatives.

Evil people were using landline phones, telegrams, and letters for evil purposes before.

#Signalgate

Show threadVon JaviMar 24
@mattblaze Think way too many people forgot of the amazing incompetence of the first Trump administration, and that probably is part on how we ended up here
Show threadHasufinMar 24
@mattblaze Notwithstanding the "oops we accidentally included a reporter in our top secret war planning", it kinda bothers me a little that the "You must return to office, if I don't see you working you're a slacker" crowd appears to themselves wholeheartedly embrace the kind of communications tech they don't want other people using. I mean, if you don't need to be in a conference room to discuss *how to invade a country*, it seems silly to require RTO for other things.
Show threadChris NeklasonMar 24

@mattblaze

Sadly, there is no defense against a classic PEBKAC attack.

(Problem Exists Between Keyboard And Chair)

Show threadAlex StrasheimMar 24
@mattblaze I think the officials on the chat probably think that it also provides protection from the USG itself, so conversations can be held without being recorded.
Show threadchroma0Mar 24

@mattblaze

I guess we need to see Signal raise their app suitability from Everyone to some sort of minimum age lol