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Comment: Re:110 or 240v (Score 3, Informative) 187

by jcochran (#47511517) Attached to: Google Offers a Million Bucks For a Better Inverter

The 240V 60Hz is so that it can handle both North American and UK voltage levels. If you look at the technical specifications document, you'll see that there are 2 different grounding configurations that the contestants may specify. In both configurations the inverter output is fed into an isolation transformer. One specification has the input of the isolation transformer center tapped and grounded which makes the AC outputs from the inverter swing +/- 120V from ground like you would expect in the USA. The other configuration doesn't have a center tapped transformer, but one leg of the input is grounded making one of the AC outputs swing +/- 240 V in referenced to ground and the other output is tied to ground. I suspect the 60Hz specification is due to the way transformers work. A transformer designed to operate at 50Hz using minimal materials will operate fine at 60Hz. However a transformer designed to operate at 60Hz using minimal materials will saturate magnetically at 50Hz causing it to overheat and eventually fail.

Comment: Re:uh huh (Score 1) 80

by jcochran (#47510587) Attached to: Researchers Test Developer Biometrics To Predict Buggy Code

And you've still avoided naming any metrics....

Number of lines of code? As mentioned earlier, one can easily inflate LOC with trash.
Also how do you evaluate a programmer who actually reduces the lines of code in a program? By the LOC metric, said programmer is counter productive. Then again you get the beautiful quote by Ken Thompson... "One of my most productive days was throwing away 1000 lines of code."

Code quality? Once again, how do you judge it?

Comment: Subpoena vs Warrent (Score 2) 749

by jcochran (#47452263) Attached to: Obama Administration Says the World's Servers Are Ours

The real issue at hand is the difference between a warrent and a subpoena.
The legal requirements to obtain a warrent are rather trivial and obtaining a warrent is rather easy. But a warrent doesn't extend past the boundaries on the United States. A subpoena on the other hand has far stricter oversight and requirements to obtain. But a subpoena requires the one served to provide the information requested regardless of where in the world that information resides.

What's happening is the government is attempting to get the best of both worlds. The trivial requirements of obtaining a warrent, combined with the expanse of a subpoena. And that frankly is wrong and needs to be stopped.

Comment: Re:Now I'm confused ... (Score 3, Insightful) 380

by jcochran (#47327837) Attached to: New Chemical Process Could Make Ammonia a Practical Car Fuel

Unfortunately, it needs to be anhydrous ammonia.
Looking at the paper, what they're doing is

1. Convert sodium amide into metallic sodium, hydrogen, and nitrogen.
2. Convert ammonia and metallic sodium into sodium amide and hydrogen.

They can easily balance those two reactions.
However, if there's any water in the system, there will be a 3rd reaction going on as well.
3. Convert water and metallic sodium into sodium hydroxide and hydrogen.
That 3rd reaction would effectively consume the sodium prevent it from making more sodium amide.

Given how nasty anhydrous ammonia is, I definitely know I wouldn't want to be anywhere near an accident involving it.

Comment: Re:Except, of course, they have to prove you can (Score 1) 560

by jcochran (#47326331) Attached to: Mass. Supreme Court Says Defendant Can Be Compelled To Decrypt Data

As all the other posters have already mentioned, your plan won't work. But way back when was finally forced to reveal through the legal system, the real email address of a user, I did a bit of a mental exercise.

How could someone create a pseudonymous remailer that would be extremely hard if not impossible to break through the legal system?

The scheme I thought up was as follows.
      1. Maintain an encrypted database of email addresses and pseudonyms.
      2. Have the key to the above mentioned database stored only in RAM and never written to any persistent storage.

The above scheme would work, but power failures and reboots would effectively destroy the database so it's not a complete solution. But to work around the power issues, add the following.
      3. A UPS to minimize power issues (not really required, but will reduce the down time)
      4. Have the key split into multiple parts and have those parts sent to multiple trusted parties in multiple legal jurisdictions. There's plenty of secret splitting techniques out there to do this. And if your escrow parties happen to be in the USA, Finland, Italy, Switzerland, etc., it would be rather difficult to have enough of them divulge the key portion that they've been entrusted with. And of course, have those parties instructed to destroy their key portion if they ever discover that legal proceedings have been engaged against you. And of course, have your lawyer instructed to inform those parties as well.

So in the above situation if you lose power, or need to reboot, the system will be in an unusable state, but will contact the escrow parties to retrieve the key parts and reconstruct the encryption key. Once this happens, it resumes normal operation. But most other governmental attacks would have a very slight chance of success.

Of course, other refinements could be added such as a periodic "ping" to the escrows informing them that things are still OK. If a sufficiently long time elapses without such a keep alive ping being received, the escrow would delete the key portion entrusted to it.

To break such a system would be extremely difficult.

Comment: Re:Except, of course, they have to prove you can (Score 2) 560

by jcochran (#47325733) Attached to: Mass. Supreme Court Says Defendant Can Be Compelled To Decrypt Data

Wouldn't work.


It's standard forensic practice to make bit level copies of media and examine the copies, not the original material. Your software can do anything it wants to with the USB stick and an overwrite simply means that a new copy is made from the original (using software and hardware under the investigators control) and they get to try again.

Comment: Re:Well, this won't backfire! (Score 1) 268

by jcochran (#47314937) Attached to: Wikipedia Editors Hit With $10 Million Defamation Suit

You just might want to take a look at the comment on the edit made to Yank Barry's wikipedia entry at 9:21 25 Jun 2014... The URL is and to save you time, here's the comment

  (Court cases: I expect we'll have better sources than TechEye sooner rather than later. And shortly after that, we can update Streisand effect.)

Unless you're willing to claim that all the editors of Wikipedia are geeks, then it looks like the Streisand effect is gonna have another edit in the near future.

Comment: Doesn't really say much (Score 4, Informative) 276

by jcochran (#47310709) Attached to: Federal Judge Rules US No-fly List Violates Constitution

The ruling doesn't ban the no fly list, it merely requires the government to make a suitable appeal process for those who are on the list. So you may expect the list to still be in use for quite a while. Additionally, Judge Brown is only on the Oregon district. So her ruling only applies to Oregon (however, it will be used as a precedent in other districts). All in all, it's still a very good ruling, but there's still a long ways to go.

Make headway at work. Continue to let things deteriorate at home.