Kien Tuong Truong
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kientuong114.bsky.social
Kien Tuong Truong
@kientuong114.bsky.social
65 followers 88 following 3 posts
PhD Student at ETH Zurich, Cryptography and more
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Reposted by Kien Tuong Truong
mirohaller.bsky.social
The call for talks for CAW 2026 (a workshop affiliated with Eurocrypt) is out!

This year's motto is "cryptography under real-world constraints and threat models", but other applied cryptography is also very welcome.

All info is on: caw.cryptanalysis.fun.
November 11, 2025 at 6:38 PM
kientuong114.bsky.social
For all the people working under the umbrella term of "Real-World Cryptography": you can't miss CAW 2026! Call for Talks is out now :)
mirohaller.bsky.social Miro Haller @mirohaller.bsky.social · 25d
The call for talks for CAW 2026 (a workshop affiliated with Eurocrypt) is out!

This year's motto is "cryptography under real-world constraints and threat models", but other applied cryptography is also very welcome.

All info is on: caw.cryptanalysis.fun.
November 12, 2025 at 11:55 PM
kientuong114.bsky.social
Congrats to @KhanhCrypto (who's not on bsky) for the IACR Grammy Award at #Eurocrypt 🥳
Guess I need to pick up the slack, see you at the next rump session! 😉
May 7, 2025 at 12:28 PM
Reposted by Kien Tuong Truong
eprint.ing.bot
Breaking and Fixing Content-Defined Chunking (Kien Tuong Truong, Simon-Philipp Merz, Matteo Scarlata, Felix Günther, Kenneth G. Paterson) ia.cr/2025/558
Abstract. Content-defined chunking (CDC) algorithms split streams of data into smaller blocks, called chunks, in a way that preserves chunk boundaries when the data is partially changed. CDC is ubiquitous in applications that deduplicate data such as backup solutions, software patching systems, and file hosting platforms. Much like compression, CDC can introduce leakage when combined with encryption: fingerprinting attacks can exploit chunk length patterns to infer information about the data. To address these risks, many systems—mainly in the cloud backup setting—have developed bespoke mitigations by mixing a cryptographic key into the chunking process. We study these keyed CDC (KCDC) schemes “in the wild”, presenting efficient key recovery attacks against five different KCDC schemes, deployed in the backup solutions Borg, Bupstash, Duplicacy, Restic, and Tarsnap. Our attacks are in a realistic threat model that relies only on weak known or chosen-plaintext capabilities. This shows, in particular, that they fail to protect against fingerprinting attacks. To demonstrate practical exploitability, we also present “end-to-end” attacks on three complete encrypted backup applications, namely Borg, Restic and Tarsnap. These build on our attacks on the underlying KCDC schemes. In an effort to tackle these problems, we introduce the first formal treatment for KCDC schemes and propose a provably secure construction that fulfills a strong notion of security. We benchmark our construction against existing (broken) approaches, showing that it has competitive performance. In doing so, we take a step towards making real-world systems that rely on KCDC more resilient to attacks. Image showing part 2 of abstract.
March 28, 2025 at 8:01 AM
Reposted by Kien Tuong Truong
kennyog.bsky.social
Our latest work is out! Breaking and repairing Content-Defined Chunking, with impact across
multiple backup systems. Read Kien Tuong Truong’s blog here: blog.ktruong.dev/breaking-cdc
Breaking and Fixing Content-Defined Chunking
A collection of my (future) writings about cryptography, music and other random stuff.
blog.ktruong.dev
March 25, 2025 at 6:10 PM
kientuong114.bsky.social
📄 New Blog Post (+paper!): Breaking and Fixing Content-Defined Chunking

To be presented at RWC 2025

blog.ktruong.dev/breaking-cdc/

Joint work with @merzsp, @winterdeaf, Felix Günther, @kennyog

We analyze Content-Defined Chunking, mostly in backup systems. Read the blog post for more!
Breaking and Fixing Content-Defined Chunking
A collection of my (future) writings about cryptography, music and other random stuff.
blog.ktruong.dev
March 25, 2025 at 6:13 PM