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+ - Reporter of an e-voting vulnerability raided in Argentina

TrixX writes: There have just been police raids at the home of an Argentinian security professional who discovered and reported several vulnerabilities in the electronic ballot system to be used next weeks for elections in the city of Buenos Aires. The vulnerabilities (exposed SSL keys and ways to forge ballots with multiple votes) had been reported to the manufacturer of the voting machines, the media, and the public about a week ago.
There have been no arrest but his computers and electronics devices have been impounded. Meanwhile, the information security community in Argentina is trying to get the media to report this notorious attempt to "kill the messenger".

+ - When Nerds Do BBQ 1 1

Rick Zeman writes: On this 4th of July, the day that Americans flock to their grills and smokers, Wired has a fascinating article on a computerized smoker designed by Harvard engineering students. They say, "In prototype form, the smoker looks like a combination of a giant pepper mill, a tandoori oven, and V.I.N.CENT from The Black Hole. It weighs 300 pounds. It has a refueling chute built into the side of it. And it uses a proportional-integral-derivative controller, a Raspberry Pi, and fans to regulate its own temperature, automatically producing an ideal slow-and-low burn."

After cooking >200 lbs of brisket fine-tuning the design, the students concluded, "“Old-school pitmasters are like, ‘I cook mine in a garbage can,’ and there’s a point of pride in that,” Parker says. “A lot of the cutting edge is when you take an art form and drag it back onto scientific turf and turn it into an algorithm. I don’t think we’ve diluted the artistic component with this."

+ - MIT's Bitcoin-Inspired 'Enigma' Lets Computers Mine Encrypted Data->

Guy Zyskind writes: On Tuesday, a pair of bitcoin entrepreneurs and the MIT Media Lab revealed a prototype for a system called Enigma, designed to achieve a decades-old goal in data security known as “homomorphic” encryption: A way to encrypt data such that it can be shared with a third party and used in computations without it ever being decrypted. That mathematical trick—which would allow untrusted computers to accurately run computations on sensitive data without putting the data at risk of hacker breaches or surveillance—has only become more urgent in an age when millions of users constantly share their secrets with cloud services ranging from Amazon and Dropbox to Google and Facebook. Now, with bitcoin’s tricks in their arsenal, Enigma’s creators say they can now pull off homomorphically encrypted computations more efficiently than ever.
Link to Original Source

Comment: Re:Helping out google's algorithm (Score 1) 70 70

Yeah, that "new law" one is f'ing annoying. It's been a "new law" since, uhm, for as long as I've been buying insurance? News flash: You pay different insurance rates based on your driving profile! WOW. They've started changing up the wording with other non sequiturs, but it's the same crap ad. (Why would the DMV give two shits about how much I'm paying for insurance?)

+ - June 30th Leap Second Could Trigger Unexpected Issues->

dkatana writes: On January 31, 2013, approximately 400 milliseconds before the official release of the EIA Natural Gas Report, trading activity exploded in Natural Gas Futures. It is believed that was the result of some fast computer trading systems being programmed to act, and have a one-second advance access to the report.

On June 30th a leap second will be added to the Network Time Protocol (NTP) to keep it synchronized with the slowly lengthening solar day.

In an article for InformationWeek Charles Babcock gives a detailed account of the issues, and some disturbing possibilities:

The last time a second needed to be added to the day was on June 30, 2012. For Qantas Airlines in Australia, it was a memorable event. Its systems, including flight reservations, went down for two hours as internal system clocks fell out of synch with external clocks.

The original author of the NTP protocol, Prof. David Mills at the University of Delaware, set a direct and simple way to add the second: Count the last second of June 30 twice, using a special notation on the second count for the record.

Google will use a different approach: Over a 20-hour period on June 30, Google will add a couple of milliseconds to each of its NTP servers' updates. By the end of the day, a full second has been added. As the NTP protocol and Google timekeepers enter the first second of July, their methods may differ, but they both agree on the time.

But that could also be problematic. In adding a second to its NTP servers in 2005, Google ran into timekeeping problems on some of its widely distributed systems. The Mills sleight-of-hand was confusing to some of its clusters, as they fell out of synch with NTP time.

Does Google's smear approach make more sense to you, or does Mills's idea of counting the last second twice work better? Do you have a better idea of how to handle this?

Link to Original Source

Comment: Re:Surprised? (Score 1) 98 98

80-bit floats are not available on any platform other than x86

The 80-bit long double is also available on the 68881, 68882 coprocessors and later 68K family members that incorporate the FPU. The Itanium also supports the 80-bit format.

But yeah... those aren't particularly common these days.

Comment: Re:Tesla enables Edison to win the endgame? (Score 1) 597 597

I said as much above.

In an AC system, that current is continuously changing, so those transmission lines are continuously radiating away some amount energy. But that's not all. If there are any conductors nearby, those E-M waves can induce a current in those conductors, and the resulting E-M waves from that induced current can drag on the AC line further. This mutual induction is how transformers work. But, along an AC transmission line, unwanted coupling results in transmission losses. So, an AC system has a built in, inherent source of losses in the alternating current itself.


In a DC system, with a fixed, perfectly resistive load, the current doesn't change, so there's no radiative losses. In the real world, though, the loading on the system is continually changing, so the actual current demand on the DC system will vary over time, and some energy will be radiated away. To some extent that can be filtered, but that's limited by the amount of storage you can put near the ends of the transmission.

Comment: Re:capacitance loss (Score 1) 597 597

Capacitors store energy, they don't dissipate it. Likewise with inductors.

Transmission lines represent both capacitive and inductive loads simultaneously. The capacitance, inductance, resistance of the transmission line together combine to form the characteristic impedance of the line. (Ok, there's one additional term: the conductance of the dielectric between the conductors. But, for high voltage transmission lines that are widely separated, this term is effectively 0.)

The characteristic impedance of a transmission line is of primary importance for determining the ideal load impedance for the line. In an impedance matched system, the maximum power will be transmitted to the load with no reflections.

Reflections can cause a phase shift between voltage and current, making a transmission line effectively look reactive or inductive. (See surge impedance loading.) This can be corrected for in the same ways as reactive or inductive loads by adding capacitance or inductance elsewhere.

If the load itself is reactive or inductive then you can get reactive power transfer. Reactive vs. inductive is in some sense a matter of sign; in one, current leads voltage, in the other current lags voltage. In both cases, current is out of phase with voltage and that's the problem to be solved.

Reactive power doesn't transmit any actual power to the load, but it still sends current through the system. Current is subject to ohmic losses (thanks to our friend I*I*R). Sending current without delivering real power subjects you to losses without any benefits.

In general, the capacitance of the transmission line itself isn't the culprit on its own. Rather, if you have a reactive load (either capacitive or inductive), or you have imperfect impedance matching between the load and the transmission line, you can get current flowing through your wires that isn't driving a load. That excess current incurs plain ol' resistive losses.

There is one way high capacitance can cause real problems for transmission line management, though. The rate of propagation of waves through a conductor slows in proportion to the square root of the product of the inductance and the capacitance. So, for a highly capacitive line, reflections move slowly through the system, and it becomes more difficult to compensate for transients. That seems to be the real bugbear for buried high-capacitance lines. Again, you're not losing to the capacitance directly, but rather to the knock on effects that lead to poorly compensated reflections and reactive power transfer in the system.

(Dr. Jetton, if you're reading this... EE305 may have been 20 years ago for me, but I haven't completely forgotten it. And Dr. Schertz... I didn't completely forget my T-line theory either. I wouldn't be surprised if either of you would point out flaws in my summary above.)

Comment: Re:Premature (Score 1) 597 597

I used 5v as an example as the linked article spoke specifically of running 5V and 12V everywhere. I agree that you really want a higher voltage for distribution. 48V goes a long way, although it still requires quite a lot more copper than 110V or 240V for the same power carrying capacity. (About 5x if I did my math correctly.)

Now, if those in-wall adaptors could store some charge locally (small capacitor bank), and you didn't have to wire for peak current, only sustained current, maybe you could get away with smaller wiring that way. I'm skeptical.

365 Days of drinking Lo-Cal beer. = 1 Lite-year