Tension and Flaws Before Health Website Crash

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Thanks to a huge effort to fix the most obvious weaknesses and the appointment at last of a single contractor, QSSI, to oversee the work, the website now crashes much less frequently, officials said. That is a major improvement from a month ago, when it was up only 42 percent of the time and 10-hour failures were common. Yet an enormous amount of work remains to be done, all sides agree.

via Tension and Flaws Before Health Website Crash – NYTimes.com.

Systems like this should require 5 9s availability from the beginning.  This means that the system should be operationally up 99.999% of the time.  This allows for around 5.7 minutes downtime per year.  I suspect companies like Amazon, Facebook, and Google meet this standard for high availability.  There are all kinds of methods and tricks to achieve this that have been learned over the past century in telecommunication systems.

In the last week of September, the disastrous results of the project’s inept management and execution were becoming fully apparent. The agency pressed CGI to explain why a performance test showed that the site could not handle more than 500 simultaneous users. The response once again exhibited the blame-shifting that had plagued the project for months.

Decoding radio-controlled bus stop displays

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I had the opportunity to observe a display stuck in the middle of its bootup sequence, displaying a version string. This revealed that the system is called IBus and it’s made by the Swedish company Axentia. Sure enough, their website talks about DARC and how it requires no return channel, making it possible to use battery-powered displays in remote areas.

Not much else is said about the system, though; there are no specs for the proprietary protocol. So I implemented the five-layer DARC protocol stack in Perl and was left with a stream of fully error-corrected packets on top of Layer 5, separated into hundreds of subchannels. Some of these contained human-readable strings with names of terminal stations. They seemed like an easy starting point for reverse engineering.

via absorptions: Decoding radio-controlled bus stop displays.

NSA infected 50,000 computer networks with malicious software

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A management presentation dating from 2012 explains how the NSA collects information worldwide. In addition, the presentation shows that the intelligence service uses ‘Computer Network Exploitation’ (CNE) in more than 50,000 locations. CNE is the secret infiltration of computer systems achieved by installing malware, malicious software.

via NSA infected 50,000 computer networks with malicious software – nrc.nl.

This article is a bit short on details.  It doesn’t say what OSs or exactly how they got malware onto victim machines.  The only way to infect a network would be to perhaps get control of its firewall or main router.  Since most people use cheap SOHO routers that might not be very difficult to swap out firmware on them that can do all kinds of things unbeknownst to its owner.   The article implies that the victim machines are PCs according to this:

One example of this type of hacking was discovered in September 2013 at the Belgium telecom provider Belgacom. For a number of years the British intelligence service – GCHQ – has been installing this malicious software in the Belgacom network in order to tap their customers’ telephone and data traffic. The Belgacom network was infiltrated by GCHQ through a process of luring employees to a false Linkedin page.

GPUs would make terrific network monitors

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The task of monitoring networks requires reading all the data packets as they cross the network, which “requires a lot of data parallelism,” Wenji said.

Wenji has built a prototype at Fermilab to demonstrate the feasibility of a GPU-based network monitor, using a Nvidia M2070 GPU and an off-the-shelf NIC (network interface card) to capture network traffic. The system could easily be expanded with additional GPUs, he said.

via Super Computing 13: GPUs would make terrific network monitors – Network World.

Targeted Internet Traffic Misdirection

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In practical terms, this means that Man-In-the-Middle BGP route hijacking has now moved from a theoretical concern to something that happens fairly regularly, and the potential for traffic interception is very real. Everyone on the Internet — certainly the largest global carriers, certainly any bank or credit card processing company or government agency — should now be monitoring the global routing of their advertised IP prefixes.

This kind of attack should not happen. You cannot carry out this kind of hijacking without leaving permanent, visible footprints in global routing that point right back to the point of interception. We believe that people are still attempting this because they believe (correctly, in most cases) that nobody is looking.

via The New Threat: Targeted Internet Traffic Misdirection – Renesys.

Understanding Packet Delivery Performance In Dense Wireless Sensor Networks

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I found this paper very useful.

ABSTRACT

Wireless sensor networks promise fine-grain monitoring  in a wide variety of environments. Many of these  environments (e.g., indoor environments or habitats) can be harsh for wireless communication. From a networking perspective, the most basic aspect of wireless communication is the packet delivery performance: the spatio-temporal characteristics of packet loss, and its  environmental dependence.

These factors will deeply impact the performance of data acquisition from these networks.

In this paper, we report on a systematic medium-scale (up to sixty nodes) measurement of packet delivery in three different environments: an indoor office building, a habitat with moderate foliage, and an open parking lot. Our  findings have interesting implications for the design and  evaluation of routing and medium-access protocols for  sensor networks.

via Understanding Packet Delivery Performance In Dense Wireless Sensor Networks

How Does the Tesla Model S Fire Risk Compare to Gasoline Cars?

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Since the Model S went into production last year, there have been more than a quarter million gasoline car fires in the United States alone, resulting in over 400 deaths and approximately 1,200 serious injuries (extrapolating 2012 NFPA data). However, the three Model S fires, which only occurred after very high-speed collisions and caused no serious injuries or deaths, received more national headlines than all 250,000+ gasoline fires combined. The media coverage of Model S fires vs. gasoline car fires is disproportionate by several orders of magnitude, despite the latter actually being far more deadly.

Reading the headlines, it is therefore easy to assume that the Tesla Model S and perhaps electric cars in general have a greater propensity to catch fire than gasoline cars when nothing could be further from the truth.

via The Mission of Tesla | Blog | Tesla Motors.

What does current look like on a quantum level?

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To understand how current flows in a material you first have to understand electrons behave in a material. The key feature of solid state physics is that many materials are crystals. This means that the atoms are spaced periodically. As you mention, band structures are the way that we summarize the effect of this periodic potential. Basically, a band structure just relates an electrons momentum p=mv=hbar k to its energy. The momentum can be positive or negative, the sign only denotes direction. In free space this is very boring, Energy=m v2 /2 = p2 /2m=hbar k2 /2m. When you throw in a periodic potential, this becomes modified and results in bands. Actually calculating band structures is quite difficult. The key idea is that there are ranges of energy where the electron can live and ranges of energy where the electron cannot live.

via What does current look like on a quantum level? : askscience.

Snapchat Spurned $3 Billion Acquisition Offer from Facebook

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In June, Snapchat raised $60 million from investors including Institutional Venture Partners; that round valued the company at $800 million.

Three months later, Snapchat said its usage had nearly doubled, to 350 million messages or “snaps” per day, up from 200 million in June.

via Snapchat Spurned $3 Billion Acquisition Offer from Facebook – Digits – WSJ.