mercredi 17 novembre 2010

Protecting journalist sources in a digital age

The need for secrecy to a journalist has been brought to the fore after three french media inquiring on the Woerth-Bettencourt state affair had been robbed in just two weeks. Laptops, GPS systems, hard drives and CD-ROM’s with data pertaining to this case have disappeared in a series of targeted burglaries. This is very bad news for the informants, and a deterrence toward those likely to hand over valuable information to the press. What can journalists do to keep confidence of the public and retain the ability to do their job in a digital age ? Let everybody know that they use state of the art techniques to protect their sources. This means that all their data, wherever they are stored, on drives or USB keys, are protected with some strong cryptography. Is it possible for non-technical people like the writers often are ? Yes. On many Linux systems, the installer displays options to use encrypted partitions. The simplest form is a cyphered /home partition, where personal data are stored. Problems may come from applications writing things elsewhere, like the /var or the /tmp directories. The swap partition may also leak some clues to nosey thefts equipped with proper recovery tools. The most secure solution is the encryption of the whole disk, but a small partition necessary to bootstrap the system. The drawback is the cost in CPU burden, as every disk write or read needs a bit of computing power. Laptops with double core can handle that but they may drain batteries fairly quickly when reading, copying or downloading many files.

How strong is an AES-128 bits key, a widely used standard for disk encryption ? Computer scientists refer this to as an NP-complete problem, meaning that there are no other (known) solution than to compute the 2128 possibilities to be sure. To give an idea of how huge this number is, Jon Callas, CTO, CSO of PGP Corp devised a nice fiction.

Imagine a computer that is the size of a grain of sand that can test keys against some encrypted data. Also imagine that it can test a key in the amount of time it takes light to cross it. Then consider a cluster of these computers, so many that if you covered the earth with them, they would cover the whole planet to the height of 1 meter. The cluster of computers would crack a 128-bit key on average in 1,000 years.

Read the article here:

I did again the math, just to be sure. If we take a sand made of cubic grains of 1 mm, which is rather coarse, but still sand, I found that the huge heap would verefie the whole key space in a bit more than 37 minutes. With a more realistic sand, say with round grains neatly packed, as they take 74% of the space and you can add more in the same volume, the solution is spit out in about 28 minutes. I guess that with such a computer, we could do more interesting things, even in a half hour. My result is somewhat different than Callas’ but doesn’t invalidate the point. The weakest link is not the algorithm, but the passphrase used to protect the key. It has to be long, 20 characters at least for a 128 bits key, almost random and at the same time easy to remember, because you don’t want to write it down. Callas points out that spy agencies use profiling and computing methods to infer it from names of relatives, loved ones, pets and important dates of life. So fellow journalists, don’t cut corners.

lundi 8 novembre 2010

Lunchtime in Paris @ Desvouges

During a lunch I had with my friend Jérôme in September 2009, he told me about his plan to start a restaurant. I knew we’ll loose a good journalist, but will we find a good restaurateur ? Now, you understand I’m writing about a friend’s shop and that I’m not going to be objective, right ? I don’t pretend to, and you shouldn’t trust journalists who do. I’m not his associate, he didn’t serve the meal for free. I was invited by an other friend, but I won’t write her praises here. Jérôme named his restaurant after him, Desvouges, which could mean he’s not modest or shy. That’s the case, but I think he simply means here his cuisine is very personal. In an other post, I talked about a eatery in Mouffetard, where tourists are provided with tired and uninspired food, where the waiter could exchange the dishes while guests wouldn’t notice. Desvouges is a kind of an antithesis. “I don’t like much Bordeaux. So, you won’t find many on the wine list”. People who taste by themselves know that Bordeaux are often overrated and that great ones are ridiculously overpriced. Instead, you find at Desvouges a reasoned, rather narrow choice of Beaujolais (Morgon, Julienas), Bourgognes, Loire wines and wines from Languedoc. These ones have long had a bad reputation. But many small winemakers bet on quality in the last twenty years. In this sunny land with light soils, some wine artisans manage to grow full-bodied and though very subtle wines. Even the best ones are affordable. If it was for those who know little about wines but brands, such a personal wine list would be quite daring. Now you guess Desvouges is dedicated to habitue and curious people. The motto “Cuisine traditionnelle” should be understood as “inspired by traditional cuisine”. The Nem Toulousain I ordered that day couldn’t be less traditional, or maybe a mixture of south east Asia and south west France traditions ? This long delicacy is made of Toulouse sausage stuff defatted, kneaded with rosemary, sage, onion stewed in olive oil, wrapped in a rice sheet, like a Chinese roll, then lightly pan-fried, served with potatoes and a home-made ratatouille. The chef likes to tell about his recipes, it is part of his pleasure to host. I’m quite picky about food quality and meat in particular. I have to admit this Nem Toulousain was a treat. And the ratatouille was a rare delight. In restaurants, the greenery beside the meat of fish is too often overlooked if not despised. French fries or french beans, hastily defrosted, have not yet disappeared. At Desvouges, vegetables receives as much respect as the choice cut. My friend Gilda had raviolis stuffed with duck comfit she described almost as good as her mother’s cooking, a reference nothing can attain, I believe. My dessert, a creme brulee was a bit too sweet to my taste. Desserts are quite decent but don’t display the same spirit as the entrees or main courses. About the coffee, I had sort of an argument with Jérôme. Let’s say it’s unexciting. I’m intractable on coffee. A real bastard if you like. Menu changes quite often, so check on the site. The week after our visit, Jérôme proposed a pork and quince stew. The price, 20 € for a main course and dessert or entree, is worth the feast. Desvouges restaurant is not opened on week-ends.

6 rue des Fossés-saint-Marcel Paris

lundi 1 novembre 2010

Lunchtime in Paris @ La petite provence

Mouffetard street neighborhood is very appreciated by tourists, especially young Americans, probably attracted by the cheap hotels and the central location. Paris is a very dense city and once you are in the district itself, everything of interest is within an hour of walk. A pedestrian way to spare the price of a metro ticket. I wouldn’t include Mouffetard in the category of interest but at least its picturesque is genuine. The tramps sleeping off the pavement were here 55 years ago, before the tourists came, or so told me my dad. The restaurants in row date back the arrival of the visitors from the world, this we can infer from the food offered : Greek, Turk, Irish, Australian, Italian, Japanese, French... You guessed Paris is not France, but despite the real estate bubble there still are real Parisians, like my friend Jean, who invited me to La petite Provence, rue du Pot de Fer, in the vicinity of Mouffetard. Myself being from Provence cuisine, I was curious about this pretender. 10 € for entrée and main course or main course and dessert is not much but common place where competitors are waiting next door alongside takeaways with even cheaper offerings. In La petite Provence, the food itself is hardly provençal or anything from an identifiable origin. The Niçoise salad I ordered was yet another betrayal of a lost legend, too bland if I except the salt in the canned fish. And no olive oil ! The main course, fish as far as I can see from the video, was prepared in exactly the same manner as the escalope of my guest. Toasted potatoes, fried vegs and a sauce whose memory has faded since last Wednesday. Little art here, but a well-tested process to deliver calibrated dishes at a sustained rate to cater hungry folks walking back from the Eiffel Tower. I suspect the cook have a kitchen operator contract. Actually,we had a pleasant meal. After a morning carrying and mounting shelves from my apartment to Jean’s, this decent and invigorating food was welcome. The waiter was a nice guy, with a PhD in cytology and a lot a humor, waiting for a better job opportunity. At least, we had a conversation, but I hoped for a better food opportunity.