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Comment: Re: So everything is protected by a 4 digit passco (Score 1) 502

by complete loony (#47942579) Attached to: Apple Will No Longer Unlock Most iPhones, iPads For Police
I was basing that on some other stuff I've read before, I might have been wrong.;

To record a single bit by changing the state of a system requires an amount of energy no less than kT, where T is the absolute temperature of the system and k is the Boltzman constant. Given that k = 1.38 × 10^16 erg/K, and that the ambient temperature of the universe is 3.2 Kelvin, an ideal computer running at 3.2 K would consume 4.4 × 10^16 ergs every time it set or cleared a bit. To run a computer any colder than the cosmic background radiation would require extra energy to run a heat pump.

So 4.4 × 10^-23 Joules minimum per bit flip * minimum of 2^128 bit flips = 1.4 * 10^16 J. Though of course our current computers are far from ideal and it would take many bit flips to test each key. Unless someone has a better source for the energy cost of computation?

The mass of the oceans is about 1.4x10^21 kg. It takes about 4,000 J to raise the temperature of 1 kg of water by 1 degree Celcius, and thus about 400,000 J to heat 1 kg of water from freezing to boiling. The latent heat of vaporization adds another 2 million J/kg. Thus the energy required to boil the oceans is about 2.4x10^6 J/kg * 1.4x10^21 kg = 3.4x10^27 J

So an ideal computer might be able to count to 2^128 without boiling the oceans (doh). It would take a 10^11 increase in energy usage per bit before boiling the oceans was impossible to avoid.

Comment: Re: So everything is protected by a 4 digit passco (Score 1) 502

by complete loony (#47941371) Attached to: Apple Will No Longer Unlock Most iPhones, iPads For Police

That's the problem with exponential functions, the human brain is too easily tricked. Doubling the bit length of a key doesn't just make it twice as hard to break.

Over the past 40-ish years, we've transitioned from 8-bit computing to 16-bit, 32 and now 64 bit is common. We might need pointers bigger than 64-bits eventually, but we will never need a pointer bigger than 256-bits in length.

The same is true of encryption, for the same reasons. We measure the strength of a crypto system based on the number of keys we would need to attempt in a brute force search. Sometimes we find mathematical short-cuts that weaken a crypto system, reducing the number of keys we need to try. But if we can't do that, we need to test every value.

Counting through all possible values of a 128-bit number would use enough energy to raise the oceans to 100 decrees Celsius and then convert all of the water to steam. This is an amount of energy that we might be able to do harness one day, if we could be bothered. Counting through all values in a 256-bit number would require capturing all of the energy released by every star we can see.

Comment: Re: Good intentions vs free time (Score 2) 182

by complete loony (#47899575) Attached to: The MOOC Revolution That Wasn't

... half of those students [watched at least one lecture], a few hundred thousand completed the course ...

These are the only statistic that matters. Who cares how many people sign up and never do anything, maybe they decided it wasn't what they expected. Maybe they don't have the time. But if people are getting something out of it, and some are putting the effort in to complete it, it looks like a success in my book.

A couple hundred thousand course completions? I'd call that a success.

Comment: Re: The federal deficit this year is $550 billion (Score 1) 126

A national credit limit of around 40% of GDP should be plenty to cover short to medium term shortfalls and entrepreneur activity. That would include all household, business and government debts. Why have we allowed the banking sector to convince us they are essential for the functioning of every part of the economy? They have a perverse incentive to encourage us to borrow, and over the last 50 years we've bought into their propaganda. Take away all of the interest payments we're currently making and our economy has a chance to thrive.

Comment: Re:The federal deficit this year is $550 billion (Score 1) 126

Where did the majority of your spending money begin its life? Bank loans. Remember that massive issue the banking sector had recently?

We need to get our economy off credit. We need to stop borrowing against every security we can find. Either we reduce our debts voluntarily, or we go bankrupt. Either way, we will reduce our debt level over the next 5-20 years. This is going to remove money from circulation. If the government runs a surplus, this will also remove money from circulation. If we stop deficit spending the economy will shrink and may falter.

Back in the 30's we were facing a similar (but much smaller) debt problem. The "new deal" in 1933(-ish) was a program of government spending that helped to reduce the impact of the Depression. When spending was cut in 1937, the economy dipped again. While the level of debt continued to drop, what finally eliminated the remaining debt was the massive spending and manufacturing to fight WWII.

Government deficit spending isn't the problem. It's the only thing that can save us from ruin as we inevitably reduce our debts.

Comment: Re:No signup without a Google Account? (Score 1) 167

by complete loony (#47684397) Attached to: Knocking Down the Great Firewall of China

I've talked with the developers before at conferences. They were (and probably still are...) using google contacts and messaging for the initial handshake in establishing connections. That may change in future.

They also weren't doing any kind of onion routing. So if they get big enough to be noticed, passive network monitoring may reveal the very social graph that lantern depends on.

Comment: Re:What? (Score 1) 393

by complete loony (#47659399) Attached to: 3 Congressmen Trying To Tie Up SpaceX

... the government doesn't create wealth.

Only if you assume;

“A network of intergenerational transfers makes the typical person a part of an extended family that goes on indefinitely. In this setting, households capitalise the entire array of expected future taxes, and thereby plan effectively with an infinite horizon” Robert Barro

When you actually dig into the assumptions of economic theories like that, they usually turn out to be completely absurd. Of course governments can create wealth. Running a deficit creates both income and money for the rest of the economy.

Banks have the same effect when they issue loans. But they can't do that forever, which is why we're having so much trouble returning the economy to "normal".

"In matrimony, to hesitate is sometimes to be saved." -- Butler