david wong

Hey ! I'm David, a security consultant at Cryptography Services, the crypto team of NCC Group . This is my blog about cryptography and security and other related topics that I find interesting.

Lattices and Tikz August 2015

I'm writing a paper, which temporary (but maybe final) title is Timing and Lattice Attacks on a Remote ECDSA OpenSSL Server: How Practical Are They Really?

(and I already have a github repo for that)

I'm explaining a few things about Lattices, taking some of the old material I already wrote for my last paper Survey: Lattice Reduction Attacks on RSA. But this time I wanted to be more pedagogical, with more graphics and illustrated examples. For reasons that I ignore lattices are seldom well explained on the internet thing. Here's a little preview, I guess you can re-use the images however you want, just don't copyright them against me :|

What are Lattices?


The Shortest Vector Problem:


The Closest Vector Problem:


How do we solve (approximate) the SVP? LLL:


and Babai's first procedure that approximates a solution to the CVP:


Well done! You've reached the end of my post. Now you can leave me a comment :)