david wong

Hey! I'm David, the author of the Real-World Cryptography book. I'm a crypto engineer at O(1) Labs on the Mina cryptocurrency, previously I was the security lead for Diem (formerly Libra) at Novi (Facebook), and a security consultant for the Cryptography Services of NCC Group. This is my blog about cryptography and security and other related topics that I find interesting.

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Fast Fourier Transform posted April 2014

So, I've learned about Fourier every year in my bachelor of Mathematics and I'm learning about the efficient algorithm dealing with the Fourier Transform in my class of Algebra right now.

I found a really nice video explaining really quick what it is, concretely.

Here's wikipedia way of showing that fourier made by LucasVB, this crazy guy doing all those math gifs you've probably seen before :) more here

There's also a visualization in d3.js here: http://bl.ocks.org/jinroh/7524988

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Long polling and webhooks posted April 2014

I remember reading about how the newly facebook chat was made using long pollings, years ago. Now with HTML5 with have sockets and webhooks made easy. I wonder if they're still using long polling now...

Anyway, Zapier. A start up that is making APIs easy, is writing a lot of interesting tutorials these last few months. Their new Chapter 7 was released and it's about polling and web hooks. And as usual it's great!

https://zapier.com/learn/apis/chapter-7-real-time-communication

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OpenSSL is written by monkeys posted April 2014

After messing around with this code for about a month I decided to write this up for the tubes in the hope that I can save some souls. I have come to the conclusion that OpenSSL is equivalent to monkeys throwing feces at the wall. It is, bar none, the worst library I have ever worked with. I can not believe that the internet is running on such a ridiculous complex and gratuitously stupid piece of code. Since circa 1998 the whole world has been trusting their secure communications to this impenetrable morass that calls itself the "OpenSSL" project. I bet that the doctors that work on that shitshow can not prescribe anything useful either!

worrying essay, read it here: https://www.peereboom.us/assl/assl/html/openssl.html

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Heartbleed : serious vulnerability in open SSL posted April 2014

We have tested some of our own services from attacker’s perspective. We attacked ourselves from outside, without leaving a trace. Without using any privileged information or credentials we were able steal from ourselves the secret keys used for our X.509 certificates, user names and passwords, instant messages, emails and business critical documents and communication.

A pretty bad bug has been found in open SSL during the Codenomicon. more info here: http://heartbleed.com/

List of vulnerable websites from the Alexa top 10,000 websites: https://gist.github.com/dberkholz/10169691

You can test a website here: http://filippo.io/Heartbleed/

And also, if you have a lot of time to waste, this random dude seems to know a lot about it :D

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Decentralized Market Place posted March 2014

Some people from Stanford are planning to build an anonymous market place. As Silk Road as shown, such a project can only fall with time unless it is decentralized. With all the new ideas and technologies coming into place (in protocols such as bitcoins, namecoins (for dns)), they are thinking of applying them for a decentralized market place as well.

More info here: https://mailman.stanford.edu/pipermail/liberationtech/2014-March/013304.html

And a new github repo to watch out for!

https://github.com/goshakkk/decentralized-anonymous-marketplace-concept

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