Tibor Jager
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tiborj.bsky.social
Tibor Jager
@tiborj.bsky.social
350 followers 210 following 81 posts
Cryptography Researcher at Bergische University Wuppertal. Seeking wisdom, but hasn’t found it yet.
Posts Replies Media Videos
Reposted by Tibor Jager
michae.lv
The proposed social media ban, the EU KIDS Act, is perhaps the most chaotic law I have ever read!

New paper: Are EU Kidding Me? Notes from a Poorly Drafted Social Media Ban. files.michae.lv/papers/veale_areEUkiddingme.pdf

In the spirit of the proposal I have stayed offline and read no takes.
In September 2026, the European Commission published a proposed EU KIDS Act, responding to the demand for restrictions and further design obligations applying to digital services accessible to children, including social media. This Article argues that regardless of what one believes about the merits of this policy direction, the EU KIDS Act is not the legislative text we need. The scope and drafting are little short of chaotic, full of holes, enormous ambiguities, and unintended consequences. Recitals contradict articles. The use of scope borrowed from other pieces of legislation not designed for this purpose brings services into scope that should not be subject to the relevant provisions, like book-recommendation websites, music services, or exercise trackers. The infrastructural requirement for assurance of age and parental responsibility attestation simply omits enormous issues of complex families and childhoods. Complex design obligations are written in ways that can be plausibly interpreted as implicitly prohibiting entire swathes of products, such as voice assistants. This Article outlines these issues, and many more. The Commission should withdraw this proposal and reissue a workable and realistic text.
October 1, 2026 at 6:08 PM
Reposted by Tibor Jager
terliwetter.bsky.social
Wissenschaftsleugnung tötet.

Wit sind im Zeitalter der Idiotie angekommen. 😡
muellershewrote.com Allison Gill @muellershewrote.com · 13d
This is an entirely new phenomenon because before the vaccine, most women who survived measles were immune because they had it when they were young. But now, idiots who refuse to get vaccinated are giving birth to babies with measles. Two babies have died. www.nbcnews.com/health/healt...
America had wiped out measles. Now babies are infected at birth.
Congenital measles has rarely been seen in the U.S. That’s changing as vaccination declines and more pregnant women become infected.
www.nbcnews.com
September 26, 2026 at 7:58 PM
Reposted by Tibor Jager
terliwetter.bsky.social
Guten Morgen! 2017 war alles klar. Ab 2020 hätten die CO₂ Emissionen sinken müssen. Haben Sie nicht. Die Katastrophalen Auswirkungen werden drastisch zunehmen und Menschen töten. Überall auf der Welt.

Auch bei Dir!

#Klimaignoranz tötet
terliwetter.bsky.social Özden Terli @terliwetter.bsky.social · 24d
2017 haben wir mit der @wmo-global.bsky.social zusammen diese Idee umgesetzt. Berlin im Jahr 2100, aber ein Rückblick aus der Zukunft. Anmutung ein bisschen Science-Fiction, Inhalte harte Fakten…Fast 10 Jahre her…
September 17, 2026 at 6:17 AM
Reposted by Tibor Jager
kennyog.bsky.social
Our latest “Crypto in the Wild” project, analysing secure email gateways. We give 29 cryptographic attacks on 4 different products, from SEPPmail, Cisco, Proton and CipherMail. Paper to appear at ACM CCS 2026.
eprint.ing.bot ePrint Updates @eprint.ing.bot · Sep 10
Why Johnny Should Not Delegate Email Encryption to Gateways (Andris Suter-Dörig, Matteo Scarlata, Kenneth G. Paterson) ia.cr/2026/1911
Abstract. Email encryption based on S/MIME and, to a lesser extent, PGP is widely deployed in enterprise environments, often through centralised server-side encryption gateways that decrypt and sign messages on behalf of end users. Gateways can also be run locally to implement encryption for email clients that do not natively support it. We systematically analyse the security of four such products: SEPPmail, CipherMail, Cisco Email Security Appliance, and the Proton Mail Bridge. We identify 29 attacks which allow an adversary to fully decrypt messages and confuse users on the authenticity of received emails. To this end, we exploit the legacy cryptographic primitives in S/MIME and the backwards compatibility features for PGP, adapt well-known attacks such as EFAIL (Poddebniak et al., USENIX Security 2018) to this setting, and expose novel attack vectors such as the error signals produced by email infrastructure. Our findings show that moving cryptographic operations to gateways strips important signals that email clients rely on. This re-enables attacks like EFAIL, which were largely considered resolved, and introduces exploitable features in how the security status of emails is communicated. Such systems also expose sensitive decrypted plaintext to intermediate email infrastructure, which was not designed to handle it. We conclude that delegating cryptographic operations to a gateway undermines the end-to-end security model that PGP and S/MIME were designed to provide. Image showing part 2 of abstract.
September 10, 2026 at 8:12 AM
Reposted by Tibor Jager
kennyog.bsky.social
TL;DR: using compression before encryption is much weaker than we thought. Tiny length differences can be amplified - almost without limit - and noise-based or bucketization countermeasures are then easy to bypass. Joint work with @prefix-free.bsky.social and Lenka Mareková, to appear at CCS 2026.
eprint.ing.bot ePrint Updates @eprint.ing.bot · 26d
Criminology: Refined Techniques for Compression Side-Channel Attacks (Yuanming Song, Lenka Mareková, Kenneth G. Paterson) ia.cr/2026/1972
Abstract. It has been known for two decades that performing compression before encryption is dangerous, because it introduces a side channel leaking information about plaintexts through ciphertext lengths: the compressed plaintext length may be visible in the ciphertext length, and the amount of compression obtained is plaintext-dependent; hence an adversary can obtain some leakage about the plaintext via observation of ciphertext lengths. This issue was first pointed out by Kelsey (FSE 2002) and turned into a practical plaintext recovery attack in the form of the CRIME attack on SSL and TLS by Rizzo and Duong in 2012. A long series of variations and attacks against other systems followed. Despite the known dangers, the compress-then-encrypt paradigm is still prevalent in practice today. This may be because the compression-based side channel is susceptible to noise and may require a large number of queries to enable plaintext recovery, and so can be mitigated by either adding noise (e.g. with random padding) or limiting an adversary’s interaction with the system. We demonstrate that this side channel is much more powerful than previously thought. We focus on the widely-used DEFLATE algorithm in our analysis. We present novel techniques that enable strong amplification of small length differences arising during compression. Our telescoping and chaining amplification techniques exploit the way in which DEFLATE replaces common strings by shorter back-references. Our collision-based amplification technique focusses on exploiting hash table collisions in DEFLATE implementations. This involves a deeper examination (and exploitation) of the internals of DEFLATE than in previous works. These insights result in compressed length differences growing linearly with the length of queries. Compared with length differences of a few bits or bytes in prior work, our new amplification techniques thus enable us to defeat existing noise-based countermeasures. Finally, we introduce the concept of CRIME automata, these being carefully crafted query strings that enable an attacker to exert fine control over the internal behaviour of DEFLATE and produce differences in the output lengths of the compressor according to various criteria (such as whether the DEFLATE sliding window contains a given target string). In turn, our automata are composed in a modular fashion from gadgets having different functions, including matching against target strings, performing logical operations between other gadgets, and, most importantly, amplifying differences in output lengths using the above-mentioned techniques. We provide multiple, concrete automata designs that serve different attack goals. These designs are supported by experiments and a publicly available codebase demonstrating the power, flexibility, and practical impact of our CRIME automata approach. Image showing part 2 of abstract. Image showing part 3 of abstract.
September 13, 2026 at 8:53 PM
tiborj.bsky.social
A Love Letter to My Coauthors

It's Saturday night, the deadline draws near,
EUROCRYPT deadline, finest time of year.
A paper needs proofs, a proposal is due
on Tuesday. Of course. We're writing that too.

1/4
September 13, 2026 at 12:18 PM
Reposted by Tibor Jager
giuliomattioli.bsky.social
Wow. Researchers at Leiden university and TU Delft university in the Netherlands accuse TU Munich of "gross misrepresentation" of their findings in the TUM press release of last week, which attacked EU regulations on vehicle emissions www.linkedin.com/pulse/misint...
September 5, 2026 at 12:14 PM
Reposted by Tibor Jager
heilrath.com
Es wirkt sehr deutlich, als habe man sich bei der Chemnitzer Polizei einfach entschlossen, sich lieber früher als später auf die Seite der Faschisten zu stellen und den Eid auf die fdGO über Bord zu werfen.

#Chemnitz #AdenauerSRP+ #sachsen @politicalbeauty.bsky.social
Die merkwürdige Jagd der Chemnitzer Polizei auf den ZPS-Protestbus
Die Polizei Chemnitz beschäftigt sich auffällig intensiv mit dem Adenauer-Protestbus des "Zentrums für Politische Schönheit". Auch innerhalb der Polizei sieht man das teils kritisch.
www.mdr.de
September 2, 2026 at 9:07 AM
Reposted by Tibor Jager
terliwetter.bsky.social
Jo.

CopXX- die Zahl braucht sich keiner mehr zu merken…
steurer.bsky.social Reinhard Steurer @steurer.bsky.social · Nov 9
Alles was ihr über #COP30 wissen müsst (und #COP31, #COP32...): Klimapolitik ist längst Bullshit-Bingo mit der Physik - und fast alle spielen immer noch brav ihre Rollen in dieser Farce (Medien sowieso, aber auch Wissenschafter & Aktivist*innen). Hier in 2 Minuten amüsant auf den Punkt gebracht 😂😪
September 3, 2026 at 8:28 AM
Reposted by Tibor Jager
matthewdgreen.bsky.social
What kills me about this story is that Meta’s public CSAM scanning clearly does not work, if they’re delivering ads for CSAM content. But this failure will be used as evidence that we need to add scanning for private and encrypted messages. www.bbc.com/news/article...
India: Instagram running ads promoting child sexual abuse material, BBC finds
The ads use terms including “rape” and “child video” and link to content on the messaging app Telegram.
www.bbc.com
July 4, 2026 at 2:22 PM
Reposted by Tibor Jager
iwillnotbesilenced.bsky.social
"They've done everything possible to eliminate us" — Iran captain Mehdi Taremi unleashes on FIFA and U.S. organizers
June 27, 2026 at 3:17 PM
Reposted by Tibor Jager
malb.bsky.social
Dear Journalists,

That "crosshair" you're referring to is a Celtic cross, a well-known white supremacist logo:

en.wikipedia.org/wiki/Celtic_...

www.adl.org/sites/defaul...

This is what these rioters are: white supremacists.
A screenshot of https://www.ft.com/content/bbdf1851-1255-4217-9544-e87c8044b5cb?syn-25a6b1a6=1 A screenshot of https://www.theguardian.com/uk-news/2026/jun/11/how-the-belfast-stabbing-was-the-spark-to-a-fuse-loaded-with-grievance-and-provocation
June 11, 2026 at 10:54 AM
Reposted by Tibor Jager
rwc.iacr.org
The Call for Contributed Talks for the 2027 edition of the Real World Crypto Symposium 2027 is now open.

If you’ve built, deployed, broken, measured, migrated, or learned something the community should hear about, submit it.

rwc.iacr.org/2027/contrib...
RWC 2027 call for papers
Real World Crypto Symposium
rwc.iacr.org
May 28, 2026 at 4:24 PM
tiborj.bsky.social
The best concrete bit-security one can achieve for a dlog-based construction on a 256 bit algebraic group is 128 bits, right?

Well, usually yes, but sometimes, somewhat surprisingly, better concrete security is possible:
eprint.ing.bot ePrint Updates @eprint.ing.bot · May 27
Beyond 128 Bits: The Concrete Security of EKE (Jiawei Bao, Tibor Jager, Eike Kiltz, Aysan Nishaburi, Samin Nooripoor, Jiaxin Pan) ia.cr/2026/1053
Abstract. Can a relevant cryptographic primitive, when instantiated over the NIST P-256 elliptic curve, achieve a bit-security level exceeding 128 bits? Yes. We formally prove that the well-known password-authenticated key exchange protocol EKE, introduced by Bellovin and Merritt (S&P 1992), achieves a generic security level of $128+\frac{1}{2}\log_2(N)$ bits, where N denotes the size of the password space. To prove this result, we introduce and develop a new approach for showing that breaking a cryptosystem with a prescribed advantage requires solving many instances of an underlying computational assumption. To this end, we formulate the Hidden-Target Diffie-Hellman assumption. In this assumption, the adversary is given a set of N Diffie-Hellman challenge instances. The Diffie-Hellman key of one uniformly random instance is designated as the hidden target. The adversary does not know which instance is the target, but may output an arbitrary subset of candidate solutions and succeeds only if this subset contains the target. We formally prove that breaking the Hidden-Target Diffie-Hellman assumption with probability greater than (k − 1)/N requires solving at least k of the N Diffie-Hellman instances. We then show that the security of EKE in the ideal-cipher model is equivalent to the Hidden-Target Diffie-Hellman assumption. A somewhat surprising consequence of this equivalence is that EKE achieves the claimed generic security level of $128+\frac{1}{2}\log_2(N)$ bits. Moreover, the equivalence implies that EKE remains secure even in settings where the hardness of DLOG or CDH is weaker than expected: an adversary may still need to solve on the order of hundreds or thousands of discrete logarithm instances in order to succeed, a task that may remain infeasible even for powerful attackers, including those equipped with early quantum computers. Image showing part 2 of abstract.
May 28, 2026 at 4:00 AM
Reposted by Tibor Jager
krismeana.bsky.social
Coachella is trying to wipe all of the footage of The Strokes protest set so I’m gonna post it here. The last images on the screen made me cry.
April 20, 2026 at 5:45 AM
Reposted by Tibor Jager
fridaysforfuture.de
Das die Bundesregierung in der Woche nach dem deutschen Erdüberlastungstag die Klimaziele faktisch abschaffend will, kannst du auch niemandem erzählen.

Diese Politik ist Zerstörung pur, nichts anderes!
May 10, 2026 at 4:31 PM
Reposted by Tibor Jager
cryptomaeher.bsky.social
My time at RUB is coming to an end and I'm looking for an industry position.
Primarily looking for remote or Rhine-Ruhr area positions, but will consider any exceptional offers.
So if you're looking to hire a cryptographer to work on cryptographic protocols, or related areas, maybe we should talk!
May 7, 2026 at 1:27 PM
Reposted by Tibor Jager
peterjelinek.eurosky.social
www.spiegel.de/wirtschaft/b...
Benzinpreise: Von der Zwölf-Uhr-Regel profitieren die Konzerne
Nur noch einmal am Tag dürfen laut einem neuen Gesetz die Preise an den Tankstellen erhöht werden. Eine Studie zeigt: Dadurch verdienen die Konzerne noch mehr.
www.spiegel.de
April 26, 2026 at 8:43 AM
Reposted by Tibor Jager
peterjelinek.eurosky.social
Benzin 14,1 Cent
Bei Diesel von 16,3 Cent.
Tankrabatt eingesackt.
Keine Pointe.
Rekordsprung: Spritpreise steigen vor Tankrabatt deutlich
Nach zwei Wochen Talfahrt ziehen die Spritpreise jetzt wieder kräftig an. Kurz nach dem Bundestagsbeschluss zum Tankrabatt ab 1. Mai verzeichnete der ADAC beim 12-Uhr-Mittagssprung den stärksten Ansti...
www.br.de
April 24, 2026 at 7:50 PM
Reposted by Tibor Jager
mgrill.bsky.social
Der verantwortliche Staatssekretär ist übrigens Ingo Behnel, vormals im Gesundheitsministerin die rechte Hand von Jens Spahn und zuständig für die Corona-Maskeneinkäufe
akm0803.bsky.social Ann-Katrin Müller @akm0803.bsky.social · Apr 17
Bundesfamilienministerin Karin Prien kürzt mehr als 200 Projekten bei »Demokratie leben!« das Geld. Menschen, die im Ministerium arbeiten, sagen: weil sie der Hausspitze zu links sind. Auch interne Dokumente, die wir einsehen konnten, nähren den Verdacht.
(S+) »Demokratie leben!«: Was steckt hinter dem großen Umbau bei der Demokratieförderung?
Bundesfamilienministerin Karin Prien kürzt mehr als 200 Projekten das Geld. Insider sagen: weil sie ihr zu links sind.
www.spiegel.de
April 17, 2026 at 1:43 PM
tiborj.bsky.social
I am trying to understand the cryptographic protocols used by the EU age verification app - and currently I am failing.

Is anyone able to extract how the age verification is supposed to work on a cryptographic level?

Sec. 3.4 describes issuing and presentation of attestations, but ...
Overall architecture - European Age Verification Solution
ageverification.dev
April 16, 2026 at 6:50 PM
Reposted by Tibor Jager
nadim.computer
Today, for the third time in my mother's life and for the second in my own life, we lost a home due to it being bombed by the Israeli army.
April 10, 2026 at 3:18 PM
Reposted by Tibor Jager
ajaxsinger.bsky.social
When the Germans finally took my family's village in Greece in 1944, they lined up every man between 6 and 80 next to the church and shot them while the women watched. This feels like that.
ajaxsinger.bsky.social Constant Screaming @ajaxsinger.bsky.social · Apr 5
We killed every man between 12 and 60 in a 19 square km area.
socialmedialab.ca Social Media Lab @socialmedialab.ca · Apr 5
👀 The US used MQ-9 Reaper drones to protect the missing F-15E crew member by "striking Iranian military-aged males believed to be a threat who got within three kilometres of the Airman."
April 5, 2026 at 3:49 PM
Reposted by Tibor Jager
natanael.bsky.social
gizmodo.com/group-pushin...
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
gizmodo.com
April 5, 2026 at 9:45 AM
Reposted by Tibor Jager
patrickkaczmarczyk.bsky.social
Gestern: wir wollen Politik für die „arbeitende Mitte machen.“

Heute 👇
April 2, 2026 at 2:09 PM