Top all-time · #14253
Kelby Ludwig
Personal blog · kel.bz/post · on HN as kklsecurityprogrammingmath
Kelby Ludwig writes KEL.BZ, a personal blog at kel.bz about security, programming and math. Since 2015, 5 different Hacker News readers have linked it 15 times, most often “Building lattice reduction (LLL) intuition”. It is still writing: the last post was on 2026-01-05, and you can follow it by feed.
Too few sampled comments (5) to say how often HN recommends it.?
Why HN links it
HN readers link Kelby Ludwig's posts as gentle introductions to lattice math and LLL lattice basis reduction, used in cryptanalysis, and to undergraduate linear algebra.
Summarised by Claude from a sample of 5 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Writing about software security, cryptography, and systems by Kelby Ludwig.
Most-linked posts?
- Building lattice reduction (LLL) intuition3 people · 6 mentions · first linked 2017-07-25
- The ggh cryptosystem2 people · 2 mentions · first linked 2017-04-26
What Hacker News says?
Try this. :) https://kel.bz/post/lll/ (If you work through the prerequisites and use "understanding this post" as a sort of roadmap of what you actually need to know, this gets you about 2/3rds through undergraduate linear algebra, and you can skim through nullspaces --- all in the service of learning a generally useful tool for attacking cryptosystems).
Comment linking /post/lll/
on “The Little Book of Linear Algebra”Submitted Building lattice reduction (LLL) intuition as a story · 81 points
HN discussionReaders who enjoyed lattices vs cranks may also enjoy: 1/2 Building Lattice Reduction (LLL) Intuition (2017 blog post): https://kel.bz/post/lll/ 2017 HN thread https://news.ycombinator.com/item?id=14847560 2/2 the cryptopals crypto challenges: https://cryptopals.com/ 2014 HN thread https://news.ycombinator.com/item?id=8166064 Cryptopals problem 62 "Key-Recovery Attacks on ECDSA with Biased Nonces" from set 8 "abstra…
Comment linking /post/lll/
on “Lattices vs. Cranks”Submitted Authenticated Dictionaries with Skip Lists and Commutative Hashing as a story · 3 points
HN discussionThis is super helpful context for this article, and also one of the best pieces of technical writing I've ever read: https://kel.bz/post/lll/ We talked to Martin Albrecht on the podcast a few weeks ago about the attack model on lattice cryptography (like Kyber, the NIST PQC winner); lattice basis reduction is central to that attack.
Comment linking /post/lll/
on “Celebrated Cryptography Algorithm Gets an Upgrade”Submitted Secure Password Hash Algorithm Migrations as a story · 3 points
HN discussionOne place to start might be a tutorial on principal component analysis, which will take you through some of the intuitions for applying SVD. You can also go in the direction of cryptography; here's, for instance, a really excellent LLL tutorial that builds on Graham-Schmidt: https://kel.bz/post/lll/
Comment linking /post/lll/
on “Linear Algebra for Programmers”Submitted Control planes are a useful concept as a story · 2 points
HN discussionThis looks pretty thorough with respect to the applications of lattices to attacks (ie, not ancient knapsack systems, or modern PQ systems, but rather stuff that's relevant to cryptography that's widely deployed today). I don't think anyone's done a better job of a gentle, HN-friendly intro to this kind of lattice math than Kelby Ludwig: https://kel.bz/post/lattices/ (for a backgrounder on the lattice math used in a…
Comment linking /post/lll/
on “A Gentle Tutorial for Lattice-Based Cryptanalysis [pdf]”Submitted The ggh cryptosystem as a story · 2 points
HN discussionSubmitted The Goldreich–Goldwasser–Halevi (GGH) Cryptosystem as a story · 2 points
HN discussionSubmitted User-influenced os commands are still considered harmful as a story · 2 points
HN discussionSubmitted String comparison timing attacks in Go as a story · 1 points
HN discussionSubmitted RSA-Based Key Encapsulation Mechanisms as a story · 1 points
HN discussion
