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Comment: Re:How can you screw up a power cord? (Score 1) 71

by Phil Karn (#48580039) Attached to: Lenovo Recalls LS-15 Power Cords
It's a little hard to believe it's insulation degradation despite that .au recalls website entry. When insulation degrades, you tend to get short circuits that trip circuit breakers rather rapidly. It seems more likely to be an undersized or underprotected conductor, e.g., a multistrand conductor in which flexing from improper strain relief can break most of the strands, increasing the local series resistance and heat dissipation and possibly leading to a complete conductor failure with series arcing. Only an arc-fault protector would trip on a failure like this, and those breakers are still uncommon in the US even though they're required in much new construction. It would also seem that cord failures would be more likely in North America, Japan and other 100-120V countries because a universal switching supply producing a given amount of power will require twice the line current draw and produce 4x the heat dissipation (I^2 R) in a high resistance section of cord as it would in a country with a 230-240V supply voltage.

+ - Comcast Forgets To Delete Revealing Note From Blog Post

Submitted by Anonymous Coward
An anonymous reader writes "Earlier today, Comcast published a blog post to criticize the newly announced coalition opposing its merger with Time Warner Cable and to cheer about the FCC’s decision to restart the “shot clock” on that deal. But someone at Kabletown is probably getting a stern talking-to right now, after an accidental nugget of honesty made its way into that post. Comcast posted to their corporate blog today about the merger review process, reminding everyone why they think it will be so awesome and pointing to the pro-merger comments that have come in to the FCC. But they also left something else in. Near the end, the blog post reads, “Comcast and Time Warner Cable do not currently compete for customers anywhere in America. That means that if the proposed transaction goes through, consumers will not lose a choice of cable companies. Consumers will not lose a choice of broadband providers. And not a single market will see a reduction in competition. Those are simply the facts.” The first version of the blog post, which was also sent out in an e-mail blast, then continues: “We are still working with a vendor to analyze the FCC spreadsheet but in case it shows that there are any consumers in census blocks that may lose a broadband choice, want to make sure these sentences are more nuanced.” After that strange little note, the blog post carries on in praise of competition, saying, “There is a reason we want to provide our customers with better service, faster speeds, and a diverse choice of programming: we don’t want to lose them.”"

+ - What Does The NSA Think Of Cryptographers? ->

Submitted by mikejuk
mikejuk (1801200) writes "A recently declassified NSA house magazine, CryptoLog, reveals some interesting attitudes between the redactions. What is the NSA take on cryptography?
The article of interest is a report of a trip to the 1992 EuroCrypt conference by an NSA cryptographer whose name is redacted.We all get a little bored having to sit though presentations that are off topic, boring or even down right silly but we generally don't write our opinions down. In this case the criticisms are cutting and they reveal a lot about the attitude of the NSA cryptographers. You need to keep in mind as you read that this is intended for the NSA crypto community and as such the writer would have felt at home with what was being written.
Take for example:
Three of the last four sessions were of no value whatever, and indeed there was almost nothing at Eurocrypt to interest us (this is good news!). The scholarship was actually extremely good; it’s just that the directions which external cryptologic researchers have taken are remarkably far from our own lines of interest.
It seems that back in 1992 academic cryptographers were working on things that the NSA didn't consider of any importance. Could things be the same now?
The gulf between the two camps couldn't be better expressed than:
The conference again offered an interesting view into the thought processes of the world’s leading “cryptologists.” It is indeed remarkable how far the Agency has strayed from the True Path.
The ironic comment is clearly suggesting that the NSA is on the "true path" whatever that might be.
Clearly the gap between the NSA and the academic crypto community is probably as wide today with the different approaches to the problem being driven by what each wants to achieve. It is worth reading the rest of the article."

Link to Original Source

Comment: Moving is always an option (Score 1) 405

by gowen (#48380129) Attached to: Ask Slashdot: How To Unblock Email From My Comcast-Hosted Server?

"When I ask my other tech friends what they would do, they simply suggest changing ISPs. Nobody likes Comcast, but I don't have a choice here. I'm two years into a three-year contract. So, moving is not an option"

Moving is always an option. But you have to eat the cost of one year of Comcast. Sorry, but that's your solution.

Comment: Re:Sounds like what Sun did (Score 1) 525

You seem to think that realeasing something as Open Source magically causes it to run well on all platforms. It takes work to port the code to different platforms and a commitment to mainaining and reression testing the stack on all those platforms. You need to provide motive to do all that, which is never going to happen. The people who are qualified to develop on and for Linux won't touch it with a ten foot pole.

Comment: Re:LMFAO (Score 1) 139

by Phil Karn (#48291031) Attached to: World War II Tech eLoran Deployed As GPS Backup In the UK
Because of inherent drift, inertial navigation is inherently suited only to fast vehicles that get to where they're going in just a few minutes or hours, e.g., planes and missiles. Cargo ships do not qualify. It is best combined with GPS to "flywheel" through outages (e.g., vehicles in tunnels) and so it can be automatically recalibrated whenever GPS is available.

Besides LORAN-C, there used to be another low frequency radio navigation system even better suited for global shipping: Omega. It operated on even lower frequencies, in the 10-14 kHz (yes, kHz) range, and had worldwide reach unlike LORAN-C which was only regional. It was shut down in 1997.

Comment: good to have backups (Score 1) 139

by Phil Karn (#48291001) Attached to: World War II Tech eLoran Deployed As GPS Backup In the UK
I certainly wouldn't bet that GPS satellites couldn't be destroyed, but most anti-sat weapons demonstrated so far work only on low altitude orbits. The US systems consist essentially of lobbing a small suborbital missile up in the path of the target satellite. Destroying a GPS satellite in a 20,000 km orbit takes a much bigger launch vehicle and considerably more time, and would be much harder to conceal from US space sensors.

Jamming and spoofing are the much bigger threats.

Comment: are you sure? (Score 3, Informative) 139

by Phil Karn (#48290979) Attached to: World War II Tech eLoran Deployed As GPS Backup In the UK
LORAN-C would probably be rather resistant to EMP. Like just about everything military, the transmitting equipment would be designed to be EMP-resistant, and receiving equipment on vehicles would not be particularly susceptible. It's stuff with long cables that picks up EMP. LORAN-C is certainly much more jam-resistant than GPS. The transmitter power levels are/were enormously higher, some in the megawatt range, to overcome natural background noise and antenna inefficiency. Even the large towers used are only a small fraction of a wavelength (3 km). Also, LORAN-C operates by groundwave propagation (that's why the frequency is so low) so it's not very sensitive to solar activity.

Comment: Re:Meanwhile, in the U.S. (Score 1) 139

by Phil Karn (#48290615) Attached to: World War II Tech eLoran Deployed As GPS Backup In the UK
Actually, the US military has a very simple way of selectively shutting down GPS: they locally jam the L1 frequency. The satellites also transmit on a second frequency, L2, with an encrypted, high precision "P(Y)" code for which the keys are closely controlled. They have receivers that can work with just the P(Y)-code, so it doesn't matter to them if L1 is jammed.

Comment: Re:For all the idiots (Score 2) 87

by Zero__Kelvin (#48274455) Attached to: Vulnerabilities Found (and Sought) In More Command-Line Tools
No. I think I understnd how to interpret a commit log. If the commit was from a trusted source, ignore it. You have just narrowed down your search by at least 2 orders of magnitude. If you have a suspected commiter, scrutinize them. Commit logs go a very long way to taking your OMFG How will anyone analyze every change! to a pleasant rejoicing song of: Hey, it turns out we only have to review a very small subset!

Brain damage is all in your head. -- Karl Lehenbauer

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