Lightnews — Scholar-powered news

Muhammed Esgin

@mfesgin.bsky.social

140 followers 97 following 20 posts

Lecturer @MonashUni. Interested in various aspects of crypto(graphy): privacy-enhancing, quantum-safe, lattice-based, zero-knowledge, blockchain, … technologies Website: https://mfesgin.github.io

mfesgin.github.io

Posts Media Videos Starter Packs

Pinned

Muhammed Esgin @mfesgin.bsky.social · Jan 22

We're hiring multiple PhD candidates for our ARC-funded project on fully-homomorphic encryption (FHE), SNARKs & more

Job listing 👇
iacr.org/jobs/item/3840

Apply via
docs.google.com/forms/d/e/1F...

Some info on PhD at Monash/in Australia
mfesgin.github.io/supervision/

Please help to share!

Fully Funded PhD student

iacr.org

5 6

Muhammed Esgin @mfesgin.bsky.social · Jun 3

Thanks!

Muhammed Esgin @mfesgin.bsky.social · Jun 2

Our work on multi-message multi-recipient public key encryption is out! We build on Kyber (ML-KEM) and get great efficiency. Kudos to Hongxiao Wang for leading this work!

ePrint Updates @eprint.ing.bot · Jun 2

Post-Quantum Multi-Message Public Key Encryption from Extended Reproducible PKE (Hongxiao Wang, Ron Steinfeld, Markku-Juhani O. Saarinen, Muhammed F. Esgin, Siu-Ming Yiu) ia.cr/2025/1000

Abstract. A multi-message multi-recipient Public Key Encryption (mmPKE) enables batch encryption of multiple messages for multiple independent recipients in one go, significantly reducing costs, particularly bandwidth, compared to the trivial solution of encrypting each message individually. This capability is especially critical in the post-quantum setting, where ciphertext length is typically significantly larger than the corresponding plaintext.

In this work, we first observe that the generic construction of mmPKE from reproducible PKE proposed by Bellare et al. (PKC ’03) does not apply in the lattice-based setting because existing lattice-based PKE schemes do not fit the notion of reproducible PKE. To this end, we first extend their construction by proposing a new variant of PKE, named extended reproducible PKE (XR-PKE), which enables the reproduction of ciphertexts via additional hints. However, standard lattice-based PKE schemes, such as Kyber (EuroS&P ’18), do not readily satisfy the XR PKE requirements. To construct XR-PKE from lattices, we introduce a novel technique for precisely estimating the impact of such hints on the ciphertext security while also establishing suitable parameters. This enables us to instantiate the first CPA-secure mmPKE and Multi-Key Encapsulation Mechanism (mmKEM) from the standard Module Learning with Errors (MLWE) lattice assumption, named mmCipher-PKE and mmCipher-KEM, respectively. We then extend our works to the identity-based setting and construct the first mmIBE and mmIB-KEM schemes. As a bonus contribution, we explore generic constructions of adaptively secure mmPKE, achieving security against adaptive corruption and chosen-ciphertext attacks.

We also provide an efficient implementation and thorough evaluation of the practical performance of our mmCipher. Our results show that mmCipher provides significant bandwidth and computational savings in practice, compared to the state-of-the-art. For example, for 1024 recipients, our mmCipher-KEM achieves a 23~45 times reduction in bandwidth overhead, reaching within 4~9% of the plaintext length (near optimal bandwidth), while also offering a 3~5 times reduction in computational cost.

1 2 3

Muhammed Esgin @mfesgin.bsky.social · Mar 20

We’re getting close to ePrint 2025/555… is everyone ready for a new cryptography meltdown?
#ePrint555

Muhammed Esgin @mfesgin.bsky.social · Feb 21

🎥 The recording of our inaugural Distinguished Lecture by Prof Martin Hellman is now available.

Thanks to the big crowd who joined the session and for all the great questions!

Recording link 👇
www.monash.edu/it/events/20...

#OpenScience #GlobalSecurity #Cryptography

Muhammed Esgin @mfesgin.bsky.social · Feb 19

Thanks for joining!

Muhammed Esgin @mfesgin.bsky.social · Feb 18

Just one day away from our Distinguished Lecture by ACM Turing Award recipient Prof Martin Hellman on The Imperative for Open Science and the future of geopolitical security!

This is a talk not to be missed! It’s online, free & open to anyone interested!

events.humanitix.com/distinguishe...

Muhammed Esgin @mfesgin.bsky.social · Jan 30

We’re honoured to host a distinguished lecture by Turing Award recipient Prof Martin Hellman on “The Imperative for Open Science”.

The talk is online and open to anyone interested to join.

See the attached image for more details

1 3

Reposted by Muhammed Esgin

coyotebroad (Jayne Cravens) @coyotebroad.bsky.social · Jan 23

The wonderful @eff.org has an equally wonderful guide you can use to make it MUCH harder for Meta / Facebook / Instagram to collect and monetize your personal data. It's not super easy - offer to do this for family & neighbors who might not be able to: www.eff.org/deeplinks/20...

Mad at Meta? Don't Let Them Collect and Monetize Your Personal Data

If you’re fed up with Meta right now, you’re not alone. Meta tracks you across millions of websites and apps and its business model relies on your data. If you want to limit Meta’s ability to collect ...

www.eff.org

7 110 220

Reposted by Muhammed Esgin

Daniel Slamanig @drl3c7er.bsky.social · Jan 24

We are organising the International Workshop on Foundations and Applications of Privacy-Enhancing Cryptography (PrivCrypt) - co-located with ACNS 2025 end of June in beautiful Munich.

Submission deadline is March 21, 2025 (AoE).

Please help spread the word! 🙏

privcryptworkshop.github.io

PrivCrypt 2025

privcryptworkshop.github.io

7 15

Reposted by Muhammed Esgin

Olivier @gloupin.bsky.social · Jan 23

Ecole Polytechnique is hiring 4 assistant prof / full prof in cybersecurity. (Crypto, networks, forensics, ...)

Team application are welcome!

gargantua.polytechnique.fr/siatel-web/a...

Come join us!

Gargantua École polytechnique

Gargantua 8

gargantua.polytechnique.fr

2 4

Muhammed Esgin @mfesgin.bsky.social · Jan 22

Fully Funded PhD student

iacr.org

5 6

Muhammed Esgin @mfesgin.bsky.social · Jan 17

There is also the many months long visa processes…

Muhammed Esgin @mfesgin.bsky.social · Jan 11

Big congratulations!

Reposted by Muhammed Esgin

Clément Canonne @ccanonne.github.io · Jan 10

💡 Making slides, giving talks, and looking for illustrations for Alice, Bob, and the whole crew? Simón Oya (UBC) has drawn fresh, beautiful ones and releasing them under CC BY-SA 4.0 license: simonoya.com/drawings/

(discovered through the #EnCOREPrivacy25 workshop)

This is a low-res sprite sheet of the pictures available

7 22

Reposted by Muhammed Esgin

Matteo Maffei @matteomaffei.bsky.social · Jan 8

Congratulations to @erkantairi.bsky.social , former PhD student in the Security and Privacy Group at TU Wien, on his FWF Schrödinger fellowship, which will allow him to spend 2 years at UC Berkeley and then 1 year at IST Austria. I am very proud of you and all the best for the future!

1 2 12

Reposted by Muhammed Esgin

Martin R. Albrecht @malb.bsky.social · Jan 3

Khanh and Eamonn are organising UK Crypto Day on 20 February at King's College London.

Registration is free (and open) but required: uk-crypto-day.github.io/2025/02/20/u...

Help us spread the word and see you there.

UK Crypto Day: 20 February 2025

Schedule

uk-crypto-day.github.io

13 15

Muhammed Esgin @mfesgin.bsky.social · Jan 2

In real-life applications, each key share typically is held by a different entity and become its key. So compromising an entity’s key does not compromise the secret message

Muhammed Esgin @mfesgin.bsky.social · Jan 2

To add, there is also an approach called Threshold Cryptography where the main secret key is split into multiple “shares” and comprising one key share basically does not help. Access to sufficiently many key shares is needed to infer something meaningful (like recovering the message)

1 1

Muhammed Esgin @mfesgin.bsky.social · Dec 20

This is a significant result if correct in my view. I didn’t check the technical details yet, but they get Dilithium-like signature but with about 3x reduction in signature size; almost as compact as Falcon.

Muhammed Esgin @mfesgin.bsky.social · Dec 19

Apparently one does not need to fly very long to do this..

Muhammed Esgin @mfesgin.bsky.social · Dec 18

A “heuristic” proof? What does that mean???

ePrint Updates @eprint.ing.bot · Dec 18

A Heuristic Proof of P ≠ NP (Ping Wang) ia.cr/2024/2035

Abstract. The question of whether the complexity class P equals NP is a major unsolved problem in theoretical computer science. In this paper, we introduce a new language, the Add and XNOR (the negation of exclusive or (XOR)) problem, which has the simplest structure and perfect randomness, by extending the subset sum problem. We prove that P ≠ NP as it shows that an exhaustive search is necessary to solve the Add and XNOR problem. That is, problems that are verifiable in polynomial time are not necessarily solvable in polynomial time.

1 8

Muhammed Esgin @mfesgin.bsky.social · Dec 12

Where do we email to have our competitors’ papers rejected for publication? :)

Muhammed Esgin @mfesgin.bsky.social · Dec 10

Not sure about QR-code bills, but here in Australia I believe most people just set up direct debit where the biller is automatically paid from the customer’s bank card/account (after initial authorisation). Very convenient imo

Muhammed Esgin @mfesgin.bsky.social · Dec 8

#Eurocrypt 2025 (initial) reviews are out!
Enjoy(!) Asiacrypt everyone!

Reposted by Muhammed Esgin

Matteo Maffei @matteomaffei.bsky.social · Dec 2

I have an opening for several Ph.D. positions at TU Wien. Topics of interest include formal methods for security (e.g., for crypto protocols and machine learning analysis), web security, and blockchains. Apply online at https://buff.ly/4fVSmBI by 19/12/2024

University Assistant Prae-Doc (all genders)

TU-ID: 192 | 2024 | 48 | 243843

buff.ly

4 7