Indeed! I'm going to be renting a dumpster soon for some long overdue spring cleaning. If Oslo dropped off a dumpster at my place in southern California, I'd be happy to fill it up for them a few times.
Call me when you come up with an electromagnet that attracts the aluminum, titanium, copper, carbon fiber composites and plastics that space vehicles are made from.
So once 21 million is hit...no more power is needed, because you can't generate more?
Nope, power is still needed. Mining is the process that introduces transactions into the block chain. Without mining, transactions cannot be made, and the whole system grinds to a halt. The mining reward (which eventually dwindles to zero after all 21 million bitcoins have been created) is both the process by which bitcoins are gradually created at a controlled rate, and an incentive for early adopters to bother mining before the system is widely accepted. However, mining is an essential part of the system even after all 21 million bitcoins have been created. I'd hazard a guess that not as many people will mine at that point (and thus less power will be required), as they'd be fighting over the small transaction fees instead of larger mining rewards.
When I read that, I thought 21 million is not a lot of coins for the whole world to use. It seems screwy to me.
The 21 million coins are divisible to eight decimal places, so there will be 2.1E15 indivisible units of currency to be circulated. In other words, around 300,000 units per living human at the moment (that number will be smaller by the time all of the bitcoins are mined, barring a catastrophic decrease in world population).
The other thing is that bitcoins have a finite shelf life, as opposed to precious metals which we know last almost indefinitely. Once a break is found for SHA-256 or Elliptic Curve DSA (the two cryptography primitives used by the bitcoin protocol), bitcoins will be worthless.
Contingencies for such things are already designed into the system. It's not a requirement that the system must always use SHA-256. If SHA-256 becomes too weak in the future, then the bitcoin protocol can be revised to use a replacement system. This would need to be done with planning an care, as the system does depend on the clients agreeing about what protocol is to be used. If SHA-256 was suddenly broken wide open with no warning, that might prove fatal to the system. However, it's more likely that there will be advance notice as researchers discover theoretical weaknesses and time passes before practical attacks are developed. That time will hopefully allow an orderly roll-out of a revised bitcoin protocol. If not... well, bitcoin would just be the tip of the iceberg, as an awful lot of other financial transaction systems will also be broken.
After that there is exactly ZERO point or need for mining.
Incorrect. Mining is the process that adds transactions to the block chain. If there is no mining, then the entire system grinds to a halt, and existing bitcoins cannot be spent.
The mining reward serves two purposes: 1) Gradually introduce bitcoins into the system over a period of time. 2) Provide an incentive for people to mine while the system is still young and not yet widely adopted. Once the mining rewards dwindle to zero (i.e., all of the bitcoins have been created), then transaction fees remain as an incentive to miners. Many current miners will probably drop out of the pool by the time the mining reward is reduced to zero, but mining will still be necessary to make the system work.
What unused excess electricity are you talking about? Generating plants don't just run at full capacity with the unwanted energy going to waste. They adjust their output based on demand. All of the generated energy going into the electrical grid either gets dissipated as heat due to transmission line losses (a small percentage of the total, as noted by another poster), or is used by loads connected to the electrical grid.
Been there, done that. September 11th caused more damage to the u.s than anyone could have hoped for/feared.
Sadly, I think we did more damage to ourselves following 9/11 than the attackers directly did in the attacks. The loss of life and destruction of property were awful, but the subsequent erosion of our freedom directly impacts far more people, and is a gift that keeps on taking. I can't even imagine what the lingering after effects of even a poorly-executed nuclear weapon attack on the US mainland would be, given our tendency to overreact.
I do feel safe predicting one thing, though: If NK was foolish enough to make even a botched attempt to bring an atomic bomb to the US, the act would be suicidal. I would hope that our response would be non-nuclear, but I have no doubt that it would be vicious.
Depends. I'm not familiar with the geography of Oakland's or New York's harbors, but a low yield nuke in the LA-Long Beach port would probably have (relatively) few immediate casualties. The port itself is huge, and the surrounding area relatively under-populated (compared to other areas of the city). The Hiroshima blast radius was only about 1 mile with little direct structural damage outside that radius.
Also, keep in mind that the atomic bombs dropped on Japan were detonated at an altitude calculated to maximize damage. The same bombs detonated near ground level, whether on a ship in the harbor or in a sea container stacked in a yard on land, would have somewhat lower blast radius, I think.
When I viewed the site on my iPad, there was a floating panel of Facebook/twitter/etc. share buttons on the left side that it repositioned to obscure content as I scrolled. The floating buttons duplicated fixed ones above the content. Nuke it from orbit, please.
I don't see how this is different than publishing a searchable database of unlocked doors that I found in my neighborhood, with the claim that my purpose is to improve my neighborhood's security. I do not see this as oversimplification. A group (gaggle? herd?) of tweakers could use the database to find an unlocked house whose owners are on vacation and then squat there, using it as a base to burgle other houses in my neighborhood, just as malicious hackers could host malware on a vulnerable site. It's still a dick move to publish the list of unlocked doors for all to see.
I've had two T410s at work. I have not been impressed with their quality. Both have wavy, warped case plastic in spots. Both have audible digital hash in the audio at times. One has a docking port that is too unreliable to be usable. I haven't had much experience with pre-Lenovo ThinkPads, but the Lenovo ones I've used do not strike me as having any better build quality than other brands of laptops. They certainly don't hold a candle to my MacBook Air in that area.
I remember a talk about Bletchley Park where I asked whether the germans had any codebreaking work. I still have not heard nor seen a word of it anywhere at all.
I read an account recently about German cryptanalysis of the US M-209 machine, which happens to be one of my favorites. I don't remember where I read it, though. I'll reply again if I find the link before my mind wanders too far. It is my understanding that Allied forces were aware that Germany could break the M-209 cipher, but used it for low-level traffic because the machine was so convenient for widespread field use, where we wouldn't want to risk capture of our higher level cryptosystems. Low-level tactical information often is only of value to an enemy for a short period of time; i.e., a message about a small troop movement that will happen in an hour isn't very useful the following day after it has already happened. Thus, if you believe that your enemy requires a day to break one of your codes, that code can still be useful for messages that would only be of value to them for a few hours.
If I recall correctly, Germany did do codebreaking work against the Allies, but didn't achieve the same level of success that the Allies did against their codes.
If you would like to try your hand at cryptanalysis of the M-209 and related machines, take a look at this ongoing M-209 Crypto Challenge. I solved the first problem in the series, but then had to quit working on the challenge because of other stuff that came up. I may go back and work through the other problems when I have some free time.
Good point! I mentioned elsewhere here that it's normal to pad out a message to a 5-letter boundary, but padding it out still further by copying the remainder of the sheet makes even more sense. The only drawback is that it places more burden on the communications channel, which may be a serious issue when a single radio operator needs to send all of the traffic for a number of agents and faces greater risk of capture by staying on the air longer (see Kahn's The Codebreakers for accounts of such overloaded radio operators, and their capture). But if the added traffic doesn't prove to be too risky or burdensome, then padding out messages that way would be a good way to reduce the amount of information that your adversary might infer from traffic analysis. If your situation and available keying materials allow you to routinely send large empty messages, then your adversary may not even notice when you suddenly change from standby to a high level of activity just before an important mission.
Well, that's a matter of semantics. If you implement a large-scale, properly-designed one-time pad system, but then a pair of lazy and/or ignorant code clerks re-uses individual OTP sheets for some of the traffic between them (contrary to orders and training, of course), then do we say "it's not a one-time pad system", or that "it's a misused one-time pad system"? Either statement might be arguably valid.
Or maybe all of your code clerks properly use each sheet once and then immediately destroy it, but the factory that produced the keying materials messed up and included duplicate sheets mixed into some of the books, resulting in compromise of the system. Which has actually happened, by the way. You might say that it wasn't actually an OTP system, or you might say it was an OTP system in which implementation mistakes were made which compromised some of the traffic. Those mistakes may have been unintentional errors or deliberate acts by undercover agents to weaken the system, but the folks who designed and oversaw the system intended to deploy a proper OTP system and thought that they were doing just that.
Or maybe you create an OTP system, distribute good keying material without blunders like repeated pages, but then an undercover agent runs out of keying material, has no way to obtain more, and then must choose between stopping communication, communicating in plaintext, or re-using OTP sheets to get critical information through and hoping that the adversaries don't detect the situation. I lean towards calling this situation "not OTP", but it's still a matter of semantics.
Nope. A codebook is an entirely different system than a one-time pad. Codebooks are breakable given enough traffic; see Kahn's The Codebreakers for many examples of codebook breaking in history, as well as some insight into how it's done. One-time pads are truly unbreakable if properly implemented (they can be broken if certain serious mistakes are made such as re-using a key, allowing key material to fall into the hands of an adversary, etc.). Code books and OTP can be used together, including informal code-book-like schemes such as using understood nicknames for things. For example, "Charlie" probably wasn't formally recorded in a true codebook during the Vietnam war, yet it would have been a commonly understood code word for enemy troops among US soldiers.
You are right, except for one nit-picky detail: We only have an upper bound on the message length. It's fairly common practice to pad messages out to a five-letter boundary, so the actual message may be shorter than the captured ciphertext. We also don't know whether the sender used some letter to indicate spaces or just ran the words together, both of which are common and valid practices. Cryptosystems of the era often had no provisions for numbers or symbols, which would need to be spelled out in text. Sometimes a letter would be reserved for use as a space character, such as 'Z' on the US M-209 machines, or a different letter on other Hagelin-designed machines intended for different markets. It makes sense to use the least common letter in the native language of the intended users, so for example, the CX-52 machines could be easily reconfigured in the field to use one of four letters IIRC to represent a space.
Slashdot Mirror
Indeed! I'm going to be renting a dumpster soon for some long overdue spring cleaning. If Oslo dropped off a dumpster at my place in southern California, I'd be happy to fill it up for them a few times.
I hope they were gray and had derpy eyes.
That's it! From now on, we need to make our satellites out of Velcro.
Seriously, now I'm disappointed. :)
I am wary of most people wearing a suit and tie, not just the preachers.
Call me when you come up with an electromagnet that attracts the aluminum, titanium, copper, carbon fiber composites and plastics that space vehicles are made from.
Seriously, I want one of those.
LED's don't emit radio waves.
Then you should take them back to the store for a refund.
Posting to undo mods. Nothing to see here... move along.
So once 21 million is hit...no more power is needed, because you can't generate more?
Nope, power is still needed. Mining is the process that introduces transactions into the block chain. Without mining, transactions cannot be made, and the whole system grinds to a halt. The mining reward (which eventually dwindles to zero after all 21 million bitcoins have been created) is both the process by which bitcoins are gradually created at a controlled rate, and an incentive for early adopters to bother mining before the system is widely accepted. However, mining is an essential part of the system even after all 21 million bitcoins have been created. I'd hazard a guess that not as many people will mine at that point (and thus less power will be required), as they'd be fighting over the small transaction fees instead of larger mining rewards.
When I read that, I thought 21 million is not a lot of coins for the whole world to use. It seems screwy to me.
The 21 million coins are divisible to eight decimal places, so there will be 2.1E15 indivisible units of currency to be circulated. In other words, around 300,000 units per living human at the moment (that number will be smaller by the time all of the bitcoins are mined, barring a catastrophic decrease in world population).
The other thing is that bitcoins have a finite shelf life, as opposed to precious metals which we know last almost indefinitely. Once a break is found for SHA-256 or Elliptic Curve DSA (the two cryptography primitives used by the bitcoin protocol), bitcoins will be worthless.
Contingencies for such things are already designed into the system. It's not a requirement that the system must always use SHA-256. If SHA-256 becomes too weak in the future, then the bitcoin protocol can be revised to use a replacement system. This would need to be done with planning an care, as the system does depend on the clients agreeing about what protocol is to be used. If SHA-256 was suddenly broken wide open with no warning, that might prove fatal to the system. However, it's more likely that there will be advance notice as researchers discover theoretical weaknesses and time passes before practical attacks are developed. That time will hopefully allow an orderly roll-out of a revised bitcoin protocol. If not... well, bitcoin would just be the tip of the iceberg, as an awful lot of other financial transaction systems will also be broken.
After that there is exactly ZERO point or need for mining.
Incorrect. Mining is the process that adds transactions to the block chain. If there is no mining, then the entire system grinds to a halt, and existing bitcoins cannot be spent.
The mining reward serves two purposes: 1) Gradually introduce bitcoins into the system over a period of time. 2) Provide an incentive for people to mine while the system is still young and not yet widely adopted. Once the mining rewards dwindle to zero (i.e., all of the bitcoins have been created), then transaction fees remain as an incentive to miners. Many current miners will probably drop out of the pool by the time the mining reward is reduced to zero, but mining will still be necessary to make the system work.
Unused excess electricity is a waste.
What unused excess electricity are you talking about? Generating plants don't just run at full capacity with the unwanted energy going to waste. They adjust their output based on demand. All of the generated energy going into the electrical grid either gets dissipated as heat due to transmission line losses (a small percentage of the total, as noted by another poster), or is used by loads connected to the electrical grid.
Been there, done that. September 11th caused more damage to the u.s than anyone could have hoped for/feared.
Sadly, I think we did more damage to ourselves following 9/11 than the attackers directly did in the attacks. The loss of life and destruction of property were awful, but the subsequent erosion of our freedom directly impacts far more people, and is a gift that keeps on taking. I can't even imagine what the lingering after effects of even a poorly-executed nuclear weapon attack on the US mainland would be, given our tendency to overreact.
I do feel safe predicting one thing, though: If NK was foolish enough to make even a botched attempt to bring an atomic bomb to the US, the act would be suicidal. I would hope that our response would be non-nuclear, but I have no doubt that it would be vicious.
Depends. I'm not familiar with the geography of Oakland's or New York's harbors, but a low yield nuke in the LA-Long Beach port would probably have (relatively) few immediate casualties. The port itself is huge, and the surrounding area relatively under-populated (compared to other areas of the city). The Hiroshima blast radius was only about 1 mile with little direct structural damage outside that radius.
Also, keep in mind that the atomic bombs dropped on Japan were detonated at an altitude calculated to maximize damage. The same bombs detonated near ground level, whether on a ship in the harbor or in a sea container stacked in a yard on land, would have somewhat lower blast radius, I think.
When I viewed the site on my iPad, there was a floating panel of Facebook/twitter/etc. share buttons on the left side that it repositioned to obscure content as I scrolled. The floating buttons duplicated fixed ones above the content. Nuke it from orbit, please.
I don't see how this is different than publishing a searchable database of unlocked doors that I found in my neighborhood, with the claim that my purpose is to improve my neighborhood's security. I do not see this as oversimplification. A group (gaggle? herd?) of tweakers could use the database to find an unlocked house whose owners are on vacation and then squat there, using it as a base to burgle other houses in my neighborhood, just as malicious hackers could host malware on a vulnerable site. It's still a dick move to publish the list of unlocked doors for all to see.
According to your Wikipedia link, chording keyboards date back to at least 1836. (!)
You mean Cal Tech is the home of hacker culture. MIT is the home of slacker culture.
It's Caltech, not Cal Tech. One word; little "t".
I've had two T410s at work. I have not been impressed with their quality. Both have wavy, warped case plastic in spots. Both have audible digital hash in the audio at times. One has a docking port that is too unreliable to be usable. I haven't had much experience with pre-Lenovo ThinkPads, but the Lenovo ones I've used do not strike me as having any better build quality than other brands of laptops. They certainly don't hold a candle to my MacBook Air in that area.
I remember a talk about Bletchley Park where I asked whether the germans had any codebreaking work. I still have not heard nor seen a word of it anywhere at all.
I read an account recently about German cryptanalysis of the US M-209 machine, which happens to be one of my favorites. I don't remember where I read it, though. I'll reply again if I find the link before my mind wanders too far. It is my understanding that Allied forces were aware that Germany could break the M-209 cipher, but used it for low-level traffic because the machine was so convenient for widespread field use, where we wouldn't want to risk capture of our higher level cryptosystems. Low-level tactical information often is only of value to an enemy for a short period of time; i.e., a message about a small troop movement that will happen in an hour isn't very useful the following day after it has already happened. Thus, if you believe that your enemy requires a day to break one of your codes, that code can still be useful for messages that would only be of value to them for a few hours.
If I recall correctly, Germany did do codebreaking work against the Allies, but didn't achieve the same level of success that the Allies did against their codes.
If you would like to try your hand at cryptanalysis of the M-209 and related machines, take a look at this ongoing M-209 Crypto Challenge. I solved the first problem in the series, but then had to quit working on the challenge because of other stuff that came up. I may go back and work through the other problems when I have some free time.
Good point! I mentioned elsewhere here that it's normal to pad out a message to a 5-letter boundary, but padding it out still further by copying the remainder of the sheet makes even more sense. The only drawback is that it places more burden on the communications channel, which may be a serious issue when a single radio operator needs to send all of the traffic for a number of agents and faces greater risk of capture by staying on the air longer (see Kahn's The Codebreakers for accounts of such overloaded radio operators, and their capture). But if the added traffic doesn't prove to be too risky or burdensome, then padding out messages that way would be a good way to reduce the amount of information that your adversary might infer from traffic analysis. If your situation and available keying materials allow you to routinely send large empty messages, then your adversary may not even notice when you suddenly change from standby to a high level of activity just before an important mission.
Well, that's a matter of semantics. If you implement a large-scale, properly-designed one-time pad system, but then a pair of lazy and/or ignorant code clerks re-uses individual OTP sheets for some of the traffic between them (contrary to orders and training, of course), then do we say "it's not a one-time pad system", or that "it's a misused one-time pad system"? Either statement might be arguably valid.
Or maybe all of your code clerks properly use each sheet once and then immediately destroy it, but the factory that produced the keying materials messed up and included duplicate sheets mixed into some of the books, resulting in compromise of the system. Which has actually happened, by the way. You might say that it wasn't actually an OTP system, or you might say it was an OTP system in which implementation mistakes were made which compromised some of the traffic. Those mistakes may have been unintentional errors or deliberate acts by undercover agents to weaken the system, but the folks who designed and oversaw the system intended to deploy a proper OTP system and thought that they were doing just that.
Or maybe you create an OTP system, distribute good keying material without blunders like repeated pages, but then an undercover agent runs out of keying material, has no way to obtain more, and then must choose between stopping communication, communicating in plaintext, or re-using OTP sheets to get critical information through and hoping that the adversaries don't detect the situation. I lean towards calling this situation "not OTP", but it's still a matter of semantics.
Nope. A codebook is an entirely different system than a one-time pad. Codebooks are breakable given enough traffic; see Kahn's The Codebreakers for many examples of codebook breaking in history, as well as some insight into how it's done. One-time pads are truly unbreakable if properly implemented (they can be broken if certain serious mistakes are made such as re-using a key, allowing key material to fall into the hands of an adversary, etc.). Code books and OTP can be used together, including informal code-book-like schemes such as using understood nicknames for things. For example, "Charlie" probably wasn't formally recorded in a true codebook during the Vietnam war, yet it would have been a commonly understood code word for enemy troops among US soldiers.
Neither. The correct message is "BUTT". :)
You are right, except for one nit-picky detail: We only have an upper bound on the message length. It's fairly common practice to pad messages out to a five-letter boundary, so the actual message may be shorter than the captured ciphertext. We also don't know whether the sender used some letter to indicate spaces or just ran the words together, both of which are common and valid practices. Cryptosystems of the era often had no provisions for numbers or symbols, which would need to be spelled out in text. Sometimes a letter would be reserved for use as a space character, such as 'Z' on the US M-209 machines, or a different letter on other Hagelin-designed machines intended for different markets. It makes sense to use the least common letter in the native language of the intended users, so for example, the CX-52 machines could be easily reconfigured in the field to use one of four letters IIRC to represent a space.