This post is about implementing cryptography with real objects—rods, chains, and locks—and it is going to be light on formulas and heavy on pictures. Fun! Many cryptographic schemes have real-world analogues, some less trivial than others. Digital signatures are the most obvious example, where the cryptographic scheme achieves pretty much the same task as traditional … Continue reading Cryptography in the Real World

The birthday paradox is most commonly presented as a thought experiment: How many people should be invited to a party that the odds of finding two persons sharing the same birthday be more than even? The answer is 23, which is surprisingly low and counter-intuitive. Other than the unexpectedly small numeric value, there is nothing … Continue reading ‘Tis the Season for C-Section

Having your assumptions and beliefs challenged by a group of seasoned law enforcement professionals and subject matter experts can be a rather disturbing experience. It is exactly what happened to me this week during the workshop on the role of technology in combating human trafficking, organized by Rane Johnson-Stempson, danah boyd, and the good folks … Continue reading Inconvenient Truth

Part II. For Part I see here. Having largely reproduced the main results of the Lenstra et al. paper, the next research question became identifying the root cause or causes of this vulnerability. There was no shortage of explanations put forward shortly after the paper was released, and we were able to critically examine some of … Continue reading Factoring RSA Moduli. Part II.

In my first post on this blog I would like to expand its range of topics to applied cryptography and share some interesting new findings that so far have not been reported anywhere else except a Eurocrypt'12 rump session talk. On Valentine's Day earlier this year, the paper with a somewhat enigmatic title ``Ron was … Continue reading Factoring RSA Moduli. Part I.