Nearly all DHT implementations vulnerable to 'merge' bug.

As DHT implementations proliferate and harmonise, the prospect of multiple widely-deployed applications using the same or compatiable DHT implementations is increasingly becoming a reality. There are a large and increasing number of DHT libraries out there, such as Entangled , and FreePastry, being used by an increasing number of applications.

However, most of these implementations are vulnerable to a simple but subtle bug: They have no way of distinguishing one DHT network from another. Although each application's DHT network or networks start off separate, if, by chance or deliberate action a node from a different but compatiable DHT is introduced, the 'self healing' property of DHTs will ensure that, sooner or later, the two networks become merged into a single DHT.

This is not a problem for single-purpose DHT implementations such as those used by BitTorrent or Overnet, since they generally establish a single DHT with all compatiable clients participating in any case. Nor is this a problem for networks designed with heterogenous applications in mind, such as CSpace. However, this still leaves a number of DHT libraries that don't fall into either of these categories.

If DHTs from two distinct applications using compatiable implementations become merged, the outcome ...

SMTP to HTTP gateway for your App Engine (and other) apps!

In response to a comment in the channel by someone wishing their App Engine app could receive email, I put together smtp2web, a simple service that accepts mail for an address (or your entire domain), and sends it via HTTP POST to a URL you specify. If you're running in a restricted environment such as App Engine, this means you can now receive email. Even if you're not, this is a lot simpler to use than writing your own SMTP server (or adding custom handlers to most existing servers).

Someone's already blogged about it, too.

Read this: Little Brother by Cory Doctorow

Last night, having finally found my Cybook again, I downloaded Cory Doctorow's latest novel, Little Brother. Like all his other works, it's available for free download under a creative commons license, and like all his other books, it's excellent.

Unlike his other books, Little Brother is scary. Not scary in a "something's creeping up behind you" sort of way, but scary in a "completely plausible, yet utterly terrifying" way. The book is set in the (very) near future, and is focused around some of the most surveiled people in society - no, not prison inmates, high-school children. Imagine George Orwell's 1984, only a lot more immediate. Though disturbing enough to begin with, describing as it does worrying yet (alas) completely plausible intrusions in the name of 'security', everything takes a turn for the worse when a terrorist attack sends security paranoia into overdrive.

This is not a light hearted, "fun" novel. Though I don't live in the US, what happens there in the name of the "war on terror" affects me and everyone else. Starting as it did from a plausible and worryingly immediate beginning, the plot developments followed the same pattern, making it hard ...