Sabine Oechsner
@proofnerd.bsky.social
cryptography and pretty proofs | PL-curious | everything is MPC | assistant professor @ VU Amsterdam
soechsner.de
soechsner.de
Reposted by Sabine Oechsner
STOC call for papers is out. Deadline is November 2.
acm-stoc.org/stoc202...
New rules for the AI era: limited submissions, public posting and a required video. Is it a coincidence that the camera-ready deadline is April Fools Day?
acm-stoc.org/stoc202...
New rules for the AI era: limited submissions, public posting and a required video. Is it a coincidence that the camera-ready deadline is April Fools Day?
September 17, 2026 at 8:44 PM
STOC call for papers is out. Deadline is November 2.
acm-stoc.org/stoc202...
New rules for the AI era: limited submissions, public posting and a required video. Is it a coincidence that the camera-ready deadline is April Fools Day?
acm-stoc.org/stoc202...
New rules for the AI era: limited submissions, public posting and a required video. Is it a coincidence that the camera-ready deadline is April Fools Day?
Reposted by Sabine Oechsner
“Now Lean, particularly in Navier-Stokes papers, is being used as a time-stamp, a way to claim your theorem before having to write it up properly in an explainable way.”
A sentence that would’ve been seen as the ravings of a madman just ~1 year ago.
blog.computationalcomplexity.org/2026/09/navi...
A sentence that would’ve been seen as the ravings of a madman just ~1 year ago.
blog.computationalcomplexity.org/2026/09/navi...
Navier-Stokes and Lean
I was working on this week's post on Lean after reading Kevin Hartnett's book The Proof in the Code: How a Truth Machine Is Transforming Ma...
blog.computationalcomplexity.org
September 10, 2026 at 3:33 PM
“Now Lean, particularly in Navier-Stokes papers, is being used as a time-stamp, a way to claim your theorem before having to write it up properly in an explainable way.”
A sentence that would’ve been seen as the ravings of a madman just ~1 year ago.
blog.computationalcomplexity.org/2026/09/navi...
A sentence that would’ve been seen as the ravings of a madman just ~1 year ago.
blog.computationalcomplexity.org/2026/09/navi...
Reposted by Sabine Oechsner
It is time for possible Dagstuhl proposals again! Proposals can be submitted between October 15 and November 1, 2026. For links to guidelines, more details on the process, and important dates see www.dagstuhl.de/en/institute...
Call for Proposals (Deadline November 1, 2026)
Call for Proposals (Deadline November 1, 2026)
www.dagstuhl.de
September 10, 2026 at 11:50 AM
It is time for possible Dagstuhl proposals again! Proposals can be submitted between October 15 and November 1, 2026. For links to guidelines, more details on the process, and important dates see www.dagstuhl.de/en/institute...
Reposted by Sabine Oechsner
My colleague Marc found a 20-line Lean ”proof” of Fermat’s last theorem that really fits in the margin! 😁
blog.trailofbits.com/2026/09/09/a...
blog.trailofbits.com/2026/09/09/a...
A “proof” of Fermat’s Last Theorem that fits the margin
Fermat’s margin was too narrow for his proof. Ours would have fit just fine, thanks to a wonderfully cursed Lean bug.
blog.trailofbits.com
September 9, 2026 at 1:23 PM
My colleague Marc found a 20-line Lean ”proof” of Fermat’s last theorem that really fits in the margin! 😁
blog.trailofbits.com/2026/09/09/a...
blog.trailofbits.com/2026/09/09/a...
Reposted by Sabine Oechsner
Fantastic thread on math’s over-indexing on problem solving but applies to theoretical CS and crypto as well (in fact I think TCS and crypto are worse than math in this regard). Took me a few years after my PhD to converge to this viewpoint as well but I always thought I was just odd
Let me expand upon this 🔽 and say something about AIs, mathematics, proofs, conjectures, problem-solving, goalposts, paperclips, genii and, more importantly, Campbell/Goodhart's law. 🧵⤵️ •1/38
… it turns out that, as LLMs have shown us, you can solve problems without developing any interesting math or teaching us much of worth, so the “problem solving” criterion was wrong all along (or only applicable for humans). Now this is embarrassing because it looks like the goalposts are moving. …
September 8, 2026 at 10:51 AM
Fantastic thread on math’s over-indexing on problem solving but applies to theoretical CS and crypto as well (in fact I think TCS and crypto are worse than math in this regard). Took me a few years after my PhD to converge to this viewpoint as well but I always thought I was just odd
Reposted by Sabine Oechsner
I kinda consider this a soft confession to what I was theorising
1) He admits they only care about maths in so far as it brings good PR
2) they're only interested in announcing results that make it sound like they're gonna replace mathematicians
∴) they're optimising for impressive-soundingness
1) He admits they only care about maths in so far as it brings good PR
2) they're only interested in announcing results that make it sound like they're gonna replace mathematicians
∴) they're optimising for impressive-soundingness
August 30, 2026 at 6:05 AM
I kinda consider this a soft confession to what I was theorising
1) He admits they only care about maths in so far as it brings good PR
2) they're only interested in announcing results that make it sound like they're gonna replace mathematicians
∴) they're optimising for impressive-soundingness
1) He admits they only care about maths in so far as it brings good PR
2) they're only interested in announcing results that make it sound like they're gonna replace mathematicians
∴) they're optimising for impressive-soundingness
Reposted by Sabine Oechsner
My latest for @quantamagazine.org is something a bit different from my usual fare: a first-person essay exploring what theoretical computer science has to do with computers.
Does Computer Science Need Computers? | Quanta Magazine
The theoretical side of the field doesn’t require computing machines. But many questions would never have been posed without them.
www.quantamagazine.org
August 28, 2026 at 8:04 PM
My latest for @quantamagazine.org is something a bit different from my usual fare: a first-person essay exploring what theoretical computer science has to do with computers.
Reposted by Sabine Oechsner
Travel Awards for Students and Postdoctoral Fellows for #FOCS2026: details and application process are available at focs.computer.org/2026/travel-...
Apply by ⏰ September 19!
Apply by ⏰ September 19!
Travel Support – FOCS 2026
focs.computer.org
August 24, 2026 at 8:41 PM
Travel Awards for Students and Postdoctoral Fellows for #FOCS2026: details and application process are available at focs.computer.org/2026/travel-...
Apply by ⏰ September 19!
Apply by ⏰ September 19!
Reposted by Sabine Oechsner
I wrote up a new post about what AI software finding might mean for the backdoor debate. blog.cryptographyengineering.com/2026/08/14/e...
Everything is about to “go dark”
I’m coming down from spending a few days at Usenix Security, right here in my hometown of Baltimore. This means that my days have been taken up with two kinds of conversation: first, explaini…
blog.cryptographyengineering.com
August 15, 2026 at 12:47 PM
I wrote up a new post about what AI software finding might mean for the backdoor debate. blog.cryptographyengineering.com/2026/08/14/e...
Reposted by Sabine Oechsner
If you haven’t seen it, this new paper is great. They expand on a blog post I wrote that showed you could replay encrypted reasoning blobs from AI models. And they turned it into a full jailbreak. stolen-thoughts.com
Stolen Thoughts
Encrypted chain-of-thought blocks returned by Anthropic, OpenAI and Google APIs are interchangeable across sessions, users and models. We exploit this to decode hidden reasoning at scale.
stolen-thoughts.com
August 11, 2026 at 7:08 PM
If you haven’t seen it, this new paper is great. They expand on a blog post I wrote that showed you could replay encrypted reasoning blobs from AI models. And they turned it into a full jailbreak. stolen-thoughts.com
Reposted by Sabine Oechsner
Anyway, your problem isn‘t finding the time to take notes. The problem is that taking notes is thinking and thinking has to be done by someone. women have been doing a lot of metacognition that looks like a task when it’s really thinking.
August 1, 2026 at 6:04 PM
Anyway, your problem isn‘t finding the time to take notes. The problem is that taking notes is thinking and thinking has to be done by someone. women have been doing a lot of metacognition that looks like a task when it’s really thinking.
Reposted by Sabine Oechsner
The IACR board has put forward a proposal to revamp the publishing of the general conference proceedings for Eurocrypt, Crypto, and Asiacrypt. iacr.org/hybridpropos... I would encourage members to engage in discussion about this on iacr.org/discuss
Concrete Hybrid Journal Proposal
iacr.org
July 8, 2026 at 11:11 PM
The IACR board has put forward a proposal to revamp the publishing of the general conference proceedings for Eurocrypt, Crypto, and Asiacrypt. iacr.org/hybridpropos... I would encourage members to engage in discussion about this on iacr.org/discuss
Reposted by Sabine Oechsner
The documentation now includes a section on security fixes.
mp-spdz.readthedocs.io/en/latest/se...
mp-spdz.readthedocs.io/en/latest/se...
Security Fixes — MP-SPDZ documentation
mp-spdz.readthedocs.io
July 6, 2026 at 5:10 AM
The documentation now includes a section on security fixes.
mp-spdz.readthedocs.io/en/latest/se...
mp-spdz.readthedocs.io/en/latest/se...
Reposted by Sabine Oechsner
I'm looking for a job!
I'm an experienced researcher in cryptography.
My focus is on the transition to post-quantum cryptographic protocols and protocols related to blockains.
If that sounds like someone you might want to hire or you know someone who might, let's talk!
I'm an experienced researcher in cryptography.
My focus is on the transition to post-quantum cryptographic protocols and protocols related to blockains.
If that sounds like someone you might want to hire or you know someone who might, let's talk!
July 2, 2026 at 1:48 PM
I'm looking for a job!
I'm an experienced researcher in cryptography.
My focus is on the transition to post-quantum cryptographic protocols and protocols related to blockains.
If that sounds like someone you might want to hire or you know someone who might, let's talk!
I'm an experienced researcher in cryptography.
My focus is on the transition to post-quantum cryptographic protocols and protocols related to blockains.
If that sounds like someone you might want to hire or you know someone who might, let's talk!
Reposted by Sabine Oechsner
Principles for pRHL Proofs of Cryptographic Protocols: How to Convince EasyCrypt that your Protocol is Secure (Manuel Barbosa, François Dupressoir, Cameron Low, Charlotte Mylog, Sabine Oechsner, Théo Vignon) ia.cr/2026/1334
June 30, 2026 at 12:49 AM
Principles for pRHL Proofs of Cryptographic Protocols: How to Convince EasyCrypt that your Protocol is Secure (Manuel Barbosa, François Dupressoir, Cameron Low, Charlotte Mylog, Sabine Oechsner, Théo Vignon) ia.cr/2026/1334
Reposted by Sabine Oechsner
I am looking for a (fully funded) PhD student working with me in Glasgow on provable security! www.iacr.org/jobs/item/4226
PhD Student
www.iacr.org
June 17, 2026 at 6:22 PM
I am looking for a (fully funded) PhD student working with me in Glasgow on provable security! www.iacr.org/jobs/item/4226
Reposted by Sabine Oechsner
The Workshop on Attacks in Cryptography 8 (WAC8) website is finally up, and our call for talks is open. Submit your cool cryptanalysis before July 3!
We'll also invite speakers. If you had a favorite cryptographic attack from the last two years that we should invite, please put it in the comments.
We'll also invite speakers. If you had a favorite cryptographic attack from the last two years that we should invite, please put it in the comments.
![call for talks
WAC accepts proposals for contributed talks. Submissions will be evaluated based on their relevance to the following topics:
- Cryptanalysis of deployed cryptography
- Cryptanalysis of recently suggested cryptographic schemes or primitives
- New cryptoanalytic techniques
- Systems attacks breaking cryptography or bypassing underlying assumptions
Please include the following information in your contributed talk submission.
- Title.
- Description of the talk content, including: short abstract (to be published on the website on talk acceptance), and one of the following three: extended abstract describing the talk. [preferred option], a full paper and a short description of which aspects the talk will focus on. slides for a presentation, together with either speaker notes or a short outline of the non-visual content of the talk.
- Speaker information: Name, Affiliation, Short bio (to be published on the website on talk acceptance), A brief description of the relevant experience of the speaker, e.g. links to previous talks.
Submit your proposal by email to the organizers at wac@cryptanalysis.fun by July 3, 2026 AoE.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:yks27ajyuw46dn6uli6tiurm/bafkreigijuejovnd6nkj4qv3zstquy6zypals6tqcw3by2njr4bfycyek4)
June 11, 2026 at 8:24 PM
The Workshop on Attacks in Cryptography 8 (WAC8) website is finally up, and our call for talks is open. Submit your cool cryptanalysis before July 3!
We'll also invite speakers. If you had a favorite cryptographic attack from the last two years that we should invite, please put it in the comments.
We'll also invite speakers. If you had a favorite cryptographic attack from the last two years that we should invite, please put it in the comments.
Reposted by Sabine Oechsner
Check out the latest blog post on our website by Neus Vayà, who attended #TPMPC 2026 in Denmark.
In the post, she discusses the paper “When Trying to Catch Cheaters Breaks the MPC” by Andreas Brüggemann and Thomas Schneider:
www.esat.kuleuven.be/cosic/blog/t...
In the post, she discusses the paper “When Trying to Catch Cheaters Breaks the MPC” by Andreas Brüggemann and Thomas Schneider:
www.esat.kuleuven.be/cosic/blog/t...
TPMPC 2026: “When trying to catch cheaters breaks the MPC” - COSIC
COSIC - TPMPC 2026: “When trying to catch cheaters breaks the MPC” (COSIC Cryptography Blog )
www.esat.kuleuven.be
June 10, 2026 at 1:16 PM
Check out the latest blog post on our website by Neus Vayà, who attended #TPMPC 2026 in Denmark.
In the post, she discusses the paper “When Trying to Catch Cheaters Breaks the MPC” by Andreas Brüggemann and Thomas Schneider:
www.esat.kuleuven.be/cosic/blog/t...
In the post, she discusses the paper “When Trying to Catch Cheaters Breaks the MPC” by Andreas Brüggemann and Thomas Schneider:
www.esat.kuleuven.be/cosic/blog/t...
Reposted by Sabine Oechsner
As GenAI systems do more and more, even generate proofs, the focus shifts to getting high-quality specifications. What can a *responsible* programmer do? Any solution should generate work that is *meaningful* and *moderate*. We've been working on that!
blog.brownplt.org/2026/06/09/p...
blog.brownplt.org/2026/06/09/p...
Human Judgment as a Specification
blog.brownplt.org
June 9, 2026 at 12:46 PM
As GenAI systems do more and more, even generate proofs, the focus shifts to getting high-quality specifications. What can a *responsible* programmer do? Any solution should generate work that is *meaningful* and *moderate*. We've been working on that!
blog.brownplt.org/2026/06/09/p...
blog.brownplt.org/2026/06/09/p...
Reposted by Sabine Oechsner
UNSW Sydney is hiring an associate professor and a lecturer in cryptography, and the description explicitly mentions *secure computation*. Didn't you want to live in the sunniest of the most livable cities in the world?
Associate Professor in Cryptography
Join an organisation that is shaping the future direction of cryptography and secure computation in Australia, in a senior academic role that combines research leadership, strategic contribution, and ...
external-careers.jobs.unsw.edu.au
June 5, 2026 at 5:52 AM
UNSW Sydney is hiring an associate professor and a lecturer in cryptography, and the description explicitly mentions *secure computation*. Didn't you want to live in the sunniest of the most livable cities in the world?
Reposted by Sabine Oechsner
Just read through this blogpost "Contextualising Cryptography" by @senykamara.com. It hits some of the issues I have been facing in choosing the right problems for my research, even before starting my phd (advisor reveal post coming up soon). senykamara.substack.com/p/contextual...
Contextualizing Cryptography
What Is Cryptography For?
senykamara.substack.com
June 3, 2026 at 1:30 PM
Just read through this blogpost "Contextualising Cryptography" by @senykamara.com. It hits some of the issues I have been facing in choosing the right problems for my research, even before starting my phd (advisor reveal post coming up soon). senykamara.substack.com/p/contextual...
Reposted by Sabine Oechsner
A list of principles put forth by mathematicians, for mathematicians and other researchers, regarding the use of AI in research.
"Number #9 will surprise you!"
leidendeclaration.ai
"Number #9 will surprise you!"
leidendeclaration.ai
Leiden Declaration on Artificial Intelligence and Mathematics
This declaration calls for action to address the challenges posed by the use of artificial intelligence within mathematics research.
leidendeclaration.ai
June 2, 2026 at 12:54 PM
A list of principles put forth by mathematicians, for mathematicians and other researchers, regarding the use of AI in research.
"Number #9 will surprise you!"
leidendeclaration.ai
"Number #9 will surprise you!"
leidendeclaration.ai
Reposted by Sabine Oechsner
And the website with details and registration form is up!
sites.google.com/view/sydney-...
Join us on July 22–24 at #USyd, in the @sydneycompsci.bsky.social, for a 3-day (free) intensive winter school on Interactive Proofs and the PCP Theorem! [Remote participation possible]
sites.google.com/view/sydney-...
Join us on July 22–24 at #USyd, in the @sydneycompsci.bsky.social, for a 3-day (free) intensive winter school on Interactive Proofs and the PCP Theorem! [Remote participation possible]
June 1, 2026 at 12:34 AM
And the website with details and registration form is up!
sites.google.com/view/sydney-...
Join us on July 22–24 at #USyd, in the @sydneycompsci.bsky.social, for a 3-day (free) intensive winter school on Interactive Proofs and the PCP Theorem! [Remote participation possible]
sites.google.com/view/sydney-...
Join us on July 22–24 at #USyd, in the @sydneycompsci.bsky.social, for a 3-day (free) intensive winter school on Interactive Proofs and the PCP Theorem! [Remote participation possible]
Reposted by Sabine Oechsner
Teaser: a colleague (Sasha Rubin) and I are planning a 3-day (free) "intensive Winter school" at #USyd on computational complexity: specifically, interactive proofs (IP=PSPACE) and the PCP theorem. July 22-24!
I don't know how many people here are nearby and keen, but if you are: please do join!
I don't know how many people here are nearby and keen, but if you are: please do join!
May 31, 2026 at 2:21 AM
Teaser: a colleague (Sasha Rubin) and I are planning a 3-day (free) "intensive Winter school" at #USyd on computational complexity: specifically, interactive proofs (IP=PSPACE) and the PCP theorem. July 22-24!
I don't know how many people here are nearby and keen, but if you are: please do join!
I don't know how many people here are nearby and keen, but if you are: please do join!