What the fuck are the non-GM and organic farmers in the USA supposed to do? Build a glass dome over their land?
I know what I'd do. I'd insert some gene sequences into an organic grain that prevents fruit production when pollinating Monsanto grain. It should be pretty easy, just make some cell toxin that requires proteins produced by the Roundup Ready genes in the Monsanto crop. Then I'd seed it far and wide, and watch the GM crops fail to produce year after year. Bonus points if the grain won't pollinate its own original organic source, but can pollinate itself and spread GM destruction around the world, thus leaving normal crop production untouched. It should be perfectly legal, since it doesn't have to incorporate any of the Monsanto gene sequences. It's just "incompatible" with Monsanto grain. Heh.
What makes a mathematician (even a good one) any more qualified to negotiate with peace with Iran, immigration with Mexico, trade with Canada, resolve questions on abortion, gay rights, and gun control, etc, etc -- than a plumber, a veterinarian, an accountant, or a mechanic?
Perhaps an attention to detail and a familiarity with logic? The number of people who can be fooled with blatant logical fallacies is amazing.
Somebody call me when computers have proved the Four Colo(u)r Theorem. Until then I'll be off playing CounterStrike (so I can work on my winning algorithm).
Ummmm, you might want to check up on the current four color theorem proof. The proof is computer generated and verified because it relies on enumerating all the possible base cases maps can be reduced to. As far as I've heard, no human has been able to directly verify every step of the proof because it is so large.
Charging for the service instead of overpriced garbage? God, are people so unimaginative that they can't imagine charging an accurate price for a real service or on the customer side actually paying someone for a service instead of a "product"? What about people who are smart enough to go spend a couple hours in the day spa and *not* buy the stupid creams? Don't they leave your friend in the exact same position?
That makes even less sense. How does the server authenticate the client? If the server just decrypts and serves up the data to any client that connects, what's the use of encrypting? And if the server requires authentication to serve up the data, it could implement access controls just as easily. That leaves you with keeping data secret from other users/the administrators/someone with a warrant. That's what per-user encryption is for.
The server authenticates clients the same way a traditional setup does, with usernames and passwords or host based authentication for NFS. I didn't say either of those were particularly good choices for secure file system access. scp would obviously be better, but isn't suited to realtime streaming. Mounting filesystems over an SSH tunnel or VPN between the client and server would work too. Per user encryption is probably better, but I don't know of many filesystems that support secure transparent user encryption, or of any that support group permissions. I haven't looked very thoroughly though, since I don't have a need for multiuser encryption.
BINGO! I've been reading the comments here wondering when the F someone was going to ask this. If someone runs off with my personal NAS then yeah I'm protected. If someone kicks in my door and logs in via a workstation or using their machine having observed my password this does NOTHING. Perhaps I could have a key secured on my workstation which is kewl but what about my XBMC'd XBOX? My aTV? My just about anything HTPCish that's like an appliance that wants to access it? Couldn't I just as easily have a PGP'd file that appears as a F/S for my workstations to send things too and leave the rest wide open and be just as secure?
Dead man switch? Alarm system? Simple menu-based security on the media PC with a reasonable timeout? All you really need is just a script that unmounts the encrypted drives if the wrong menu choice or action is made more than two or three times, or if no network activity has occurred for 30 minutes or something. If you're asking how to evade a dedicated surveillance team monitoring you with binoculars, wiretaps, keyboard loggers, and spyware, then I obviously have no idea. At that point, you might as well have encrypted your drives so that when you suspect you're being watched you can press a button to wipe the encrypted master keys from the disk within a few seconds instead of hours to wipe the data, since you'll probably be raided when you do it.
When users leave, their keys and passphrases should be deactivated so they can't use them later to gain unauthorized access. This is nontrivial because it implies that every file they've ever had the key for need to be re-encrypted with a new random key, which is a lot of processing. Practically speaking, it's better to assume that anyone who has access to the data has actually copied every available bit of plaintext and key material and plan the threat model and security around that assumption. In light of that, it may actually make sense to encrypt on both the client and the server. The server is assumed to have a key that no user knows, and the users have keys that the server doesn't know. Only collusion between a server administrator and a user would be sufficient to retrieve all the encryption keys necessary to do bulk decryption of stolen media, and only for the keys the user knows.
Key escrow is for users who forget their passwords. It also prevents the loss of data due to the loss of individuals (through firing, quiting, or death). Secret sharing can be used to ensure that n or more administrators are required to recover a key, for some n>0
Volume encryption only makes sense if there is a significant risk of losing physical control over the volume, i.e. on portable media. If your hypothetical server with private information is not in a secure datacenter, you're doing something wrong.
Unless you want to pay to have someone shred your used hard disks, encryption is really the only safe way to keep the data on them secure. If you want warranty replacement on dead disks, you'll probably have to send them back for an RMA with the data still on them if it's not encrypted.
A physically secure location also won't protect you from a warrant. If someone really needs to do something that violates a law somewhere, it would make sense to encrypt the disks so that recovery of the evidence is impossible. Hell, a media server with music and movies ripped to it might even fall under that category, depending on how angry the MAFIAA gets.
So, considering that a fileserver will have some form of access control anyway (in case of this NAS box, the locks on his house), why encrypt the entire volume in the first place? The first insecure client that connects makes the whole exercise moot, not to mention giving out the key to multiple users.
The key only exists on the server, the clients never see it. They just see a normal mount via NFS, SMB, or whatever. Yes, a client with spyware or a malicious user on it can pull all the unencrypted data. That's a risk that has to be mitigated if the data is important enough, but no more of a risk than a traditional unencrypted network server.
If, as the original poster suggests, a large number of people in your organization have to have access to the key for this to work, then it doesn't really add much security--stealing the key off someone may not be any harder than stealing the drive.
The server has a single key which uses it encrypt/decrypt the data on the disk. It sends plaintext to the users, or optionally uses some other encrypted protocol to get the data to the clients. The users don't see the hard disk key. Other access controls are needed to ensure they don't just steal all the data over their client connection.
No, you'd do all encryption and decryption on the clients. This also has the advantage of offloading all the CPU-intensive crypto to the clients. Some complexity is required to make this work for shared data, but it's possible.
Typical public key certificate setup. Define groups and users as keypairs, and encrypt each file's random symmetric cipher key with the public keys that should have access. It's harder to manage (just as hard as any certificate setup) and changing permissions requires re-encrypting the entire file, but it's probably necessary over unsecured networks with untrusted users.
That sort of thing has absolutely no basis in the federal government. Unless it was a bridge from one state or country to another, the federal government should stay the fuck away. This was an Alaskan issue that should have been dealt with and paid for by the Alaskan government. Where in the Constitution does it give the federal government the authority to construct such a bridge in just Alaska? Don't cite the state commerce clause because that is in between states, not just a single state.
As long as the Federal Government collects income tax, I expect most of that money to come back to fund state projects.
Since LUKS supports PKCS-5 style iterative hashing of the passphrase, it's a good idea to use that too. A million iterations only take a few seconds (10 on my 1.5Ghz Athlon) to compute at mount time, but make dictionary attacks a million times harder.
Seeing as that he uses per-volume encryption, this is pretty useless. It makes his 'server' pretty much a single-user NAS box, because as soon as another user gets an account to access the file server, they get access to the data.
As long as the server remains physically secure, and assuming there aren't gaping root privilege holes in the security, the files on the disk are still protected by the file system permissions. As long as the users can trust the admin, they don't have to trust each other.
Data encryption on a fileserver only makes sense if it is done on a per-user level. This is not News for Nerds, as this is basically just another implementation of how to encrypt your local disk.
Databases with private information like credit card or social security numbers should be on encrypted disks. Not to protect against users, but to protect against the drive being replaced or stolen before it can be wiped (secure wiping is not necessarily secure either, especially as drive technology advances, since what was wiped 5 years ago may be easily readable now).
There's really no advantage to having a server encrypt and decrypt each user's data with a different key. The server will have to know all the keys to perform the decryption at least (public keys allow secure encryption without the server knowing the private key), so it's only as secure as encrypting the entire drive and then relying on filesystem permissions. Root will always be able to read any files that are encrypted/decrypted on the server itself. If clients encrypt their files before storing them on the server, then the server can safely store everything in plaintext.
C) I see nowhere a calculation of the error margins. As a corolary of B, what's more interesting for such a calculation with wildly guessed numbers isn't just one value reached with the most likely guess, but what is the _interval_ of plausible results. If you've fed data which could be anything between 2% and 10%, then what is the result for 2% and what is the result for 10%, for a start. Don't give me the result just for 5%. And that's just one of the values there.
See page 25. The inverse question of which ranges of values are possible for a given optimal copyright term are examined, which as at least as much information as working forward from the assumed decay rates. Yes, you can get anywhere from 2 to 50 years because the market is incredibly dynamic. People are still buying Lord of the Rings because it's a very good book, but the pulp fiction of the 40's is probably making very little profit for its owners. Poetry from earlier in the 20th century is still popular, and the works of Shakespeare still sell pretty well too. To actually determine which decay values are appropriate would require statistical examination of the income from works over their copyrighted lifetime and some subjective estimate of value to society as a whole.
I don't see you arguing with the model, just the choice of initial values to work with. The choice was probably because the range examined includes the vast majority of current copyright periods. 95 year copyright is only a couple decades old, so there's very little empirical data. All that exists is anecdotal evidence of works that were going to enter the public domain but didn't, and very few of those works have any appreciable value now, at least not in terms of exclusive publishing rights and profits to the (probably deceased) owner of the work.
Hypertransport and PCI Express 2 have more than enough bandwidth to use it. For servers, caching content in RAM and streaming it out at 40 gb/s is not too outrageous.
That's an absurd thing to do, as, the fastest memory speed, I believe is nowhere even close to 40gb/sec and certainly no interface bus that I'm aware for PC's that can handle a network that fast. I don't even think PCI-Express is that quick, and that's only for graphics cards isn't it?
Hypertransport is supposed to be able to get over 8 GB/s (64gb/s) on some setups.
So, absolutely for any realistic home use, the throughput in the article is useless, since no media has currently ludicrous requirements where 4 GB of data per second can be consumed and discarded per second, and storage becomes the bottleneck for downloading. There exist applications that can benefit from transferring that much data over a network, crunching on it and being done with 4 GB datasets in a second, but they are few and far between and none really applicable for a home computer.
Well, damnit, it's my cat, and all I want is credit for my own work. It's intolerable to me for others to get to take the credit, but any procedure more costly or onerous than the takedown procedure already in place would not be worth it. And the result would be that I would be disincented to create works and post them to YouTube. So much for promoting the useful arts.
Wait, you're saying that a few greedy people would prevent you from doing something altruistic just to spite them? I guess that's just human nature, but it seems incredibly irrational. If it's really that important to you, use a digital timestamping service to prove when you created it, or watermark it or something.
Oh? See, where I come from, Turing machines and the lambda calculus are formalisms for describing and computing functions, stateless mappings from a domain to a range. Operating systems, for example, are not functions, because they are not stateless.
Operating systems are functions of software, hardware and user input. This can be represented in at least two ways. The straightforward way is just to specify the interactions with hardware and the user as part of the input to a turing machine. E.g. at every step where the operating system relies on a user or external device there is enough information supplied in the input on the tape to determine the action of the turing machine. It can even be proved that the TM never needs to examine input out of order (the turing machine must process them in temporal order since it must travel linearly along the tape.), which maintains the temporal order of operations in a real operating systems. This only works for finite inputs, which is sufficient for almost any real operating system. If infinite running time must be considered then the turing machine can be made nondeterministic at the points where external input occurs in the operating system. This causes the NTM to branch nondeterministically at every step where user input occurs, and the resulting NTM follows all possible execution paths of the operating system being modeled.
This is a common theme among functional programming languages. They want to remain as purely functional as possible (because that approach has proven to be powerful), but are unable to do so in various circumstances because they have to interact with the underlying hardware or user. For instance, Haskell has its monads. Functions, as such, are unable to maintain state. They cannot express the idea of waiting for an arbitrary condition.
Only because modern computers are made that way. ENIAC and other early computers were purely functional: Plug the wires in correctly and flip the input switches, and the answer appears on the output. All microprocessors are inherently functional, they just synchronize their functional evaluations with a clock signal so that elements of some state are loaded into the inputs of a function, and during the clock cycle the outputs stabilize and are stored to some output state. All that functional programming requires to act like a modern processor is an analog of this process, which can be generalized to monads or some other serializing method with intermediate states. As far as I know, The main reason for this design is that not all functions and not all inputs and outputs can be processed as single entities. It takes a while to type a program, and it may produce pages or gigabytes of output. Imperative processors are a method of evaluating very large functions over very large values without actually having a very very large number of transistors.
That irrelevant to his point. He's not saying mathematics isn't a useful tool in computer science. He's saying that the aims of mathematicians and computer scientists are different. Even if they use the same methods. The majority of people working on whether P=NP, or extensions to Rice's theorem (there are lots), or Oracle Machines, etc. are mathematicians. These are very different kinds of problems than computer scientists are interested in. The last computer science conference I went to had papers on Data Mining, AI, computer vision and other kinds of pattern recognition, the mathematical basis of computer security, HCI, and a multitude of other subjects.
Here you have a point. Within a research field it's rarely useful to reduce the problems to basic computer theory, unless the field is brand new and needs a solid footing. However, specialization comes at the cost of generalization, and where education is concerned I prefer a general approach so that specialization can come later with the benefits of a general understanding backing it up. People do switch fields occasionally. Research into computational theory is sti
"Mathematicians and computer scientists are pursuing fundamentally different aims, and the mathematician's tools are not as appropriate as was once supposed to the questions of the computer scientist. The primary questions of computer science are not of computational possibilities but of expressional possibilities. Computer science does not need a theory of computation; it needs a comprehensive theory of process expression."
This is fundamentally, ignorantly wrong. Anyone who has worked with lambda calculus or turing machines probably has an intuitive notion of why it's wrong too. I don't know how this dude describes "expressional possibilities", but I bet he uses the notation of set theory to do so, and probably relies on the axioms of ZFC when he's talking about the possibilities, especially when he tries to count them. What does that tell you? Apparently all he wants is some different representation, but he shouldn't make sweeping remarks about mathematics being inappropriate to talk about it. Everything in science relies on mathematics. Everything in engineering relies on mathematics. Everything in computer science relies on mathematics. If it didn't, it would be magic.
A logic circuit is not a sequence of operations. An operating system is not supposed to terminate, nor does it yield a singular solution. An operating system cannot be deterministic because it must relate to uncoordinated inputs from the outside world. Any program utilising random input to carry out its process, such...is not an algorithm
Some people like the ability to shut down an operating system. If the algorithm running the operating system can't halt, then you have DOS and you just have to kill it in the middle of whatever loop it's spinning in and hope it wasn't doing anything that wasn't written to disk properly. That's not to say that working with an entire operating system in algorithmic terms is easy, I've had numerous thoughts on the best way to interpret the actions of interrupts and timing and randomness. Perhaps the best interpretation is that the operating system algorithms are actually many small halting algorithms that are directly invoked by interrupts, and the data structures are all that remains intact over the lifetime of the operating system. Most processors have a HALT instruction for just that purpose.
So your thanks is unwelcome, obviously, as I am not the inconsiderate asshole waking you up in the middle of the night as you were so quick to assume. And just as you are in your right to emit various RF signals (within reason), I am within my right to own a powerful speaker system both in my home and in my car. What I choose to do with it, and when and where I use it is what matters, and I've always understood and respected that fact.
Well, now I have the pleasure of talking to one of the few owners of a very loud stereo who doesn't abuse it. Thanks for your consideration, I only wish more people had it. Any idea which parts of said very loud stereo system are most vulnerable to RF interference? I'm thinking the amplifier circuits themselves would be the best target, because if I could introduce enough noise in the signal going into the amplifier it would either burn the speakers out or make such an incredible racket that the owner would at least turn it down. My guess is that finding good interference frequencies would mostly be a process of trial and error with each type (and brand) of amplifier circuit.
And if we were each to hit the button when we saw something un-Utopian, then it would only truly drive the possibility to zero. (I'm postulating that some things are deterministic, at least, even if their symptoms are not always.)
There's really no way to drive the probability to zero. In the worst case, the nukes just fail to kill everyone and they survive in a ruined world. In the best case, they just fail to work at all. I suppose it's a matter of degree; the closer society approached to utopia, the more likely such a disaster would be. Probably using statistics the society could estimate a reasonable level of utopia that was "safe" to run. In other words, given a probability p of the nukes failing, only choose utopian goals with probability >> p. We already play the game right now on a limited scale with MAD, as you pointed out. Only a few people have detonators, and the probability of the system wiping out humanity entirely (which isn't even a goal) is quite low. On the other hand, not everyone believes in the multiverse. Perhaps if the leaders did, we'd already have had some nuclear wars.
Quantum computing is equally bunk since it is based on the idea that a quantum property can have multiple states simultaneously, that is, when nobody is looking. ahahaha... Reminds me of the kid I knew who insisted that he could jump as high as a tall building but only when nobody was looking. Whatever happen to empiricism? Talk about pseudoscience! Everett, Schrodinger (and his stupid cat) and that lunatic David Deutsch are crackpots of the worst kinds. Only physicists can get away with such quackery. They should all be stripped naked, tarred, feathered and paraded down Fifth Avenue in New York as an example to undergraduates. ahahaha...
Sorry, your computer now refuses to work because it no longer obeys quantum mechanics. The electrons are just stuck at the N-P junctions and nothing happens because they're all in a fully defined position with no way of jumping across it at the energy levels they have. Bump the energy up, and they behave classically and just burn their way through without any of the nice semiconductor properties that make computation with them possible.
On the upside, now you'll have a lot more time to tar and feather the quacks who made your nonfunctional computer!
've observed many times that I "should have" died. It struck me that, perhaps, I did die in an alternate universe, but I (whatever I "is") continue on in at least one of the multiverses. In those multiverses in which "I" experience the death of a close friend or family member... well... that just is how it goes. But they, too, continue in an instance of the multiverse. Perhaps I do not.
Probably the most interesting practical question is what percentage of futures include all our lost family members and friends, e.g. a heaven of some kind. Obviously it's a possibility, but what is the total probability of being a consciousness somehow past death and reunited with loved ones? My guess is that at some point we will be able to understand enough about the universe to construct just about anything we want, and very likely be able to peer back into the history of the universe with arbitrary level of detail. That means that it's possible to simply reconstruct lost people from our past history at some point, with the caveat that a lot of those reconstructed people may actually only appear to be the ones we remember, as best as our memory can recall. However, to those future selves it would all appear completely logical and sane. Likewise, some simile of you and me will exist in the future universes of our friends and loved ones, and while they may not be us in the technical sense, they may be so close that "we" won't notice it while still having nearly complete memory of who we are now.
Slashdot Mirror
What the fuck are the non-GM and organic farmers in the USA supposed to do? Build a glass dome over their land?
I know what I'd do. I'd insert some gene sequences into an organic grain that prevents fruit production when pollinating Monsanto grain. It should be pretty easy, just make some cell toxin that requires proteins produced by the Roundup Ready genes in the Monsanto crop. Then I'd seed it far and wide, and watch the GM crops fail to produce year after year. Bonus points if the grain won't pollinate its own original organic source, but can pollinate itself and spread GM destruction around the world, thus leaving normal crop production untouched. It should be perfectly legal, since it doesn't have to incorporate any of the Monsanto gene sequences. It's just "incompatible" with Monsanto grain. Heh.
What makes a mathematician (even a good one) any more qualified to negotiate with peace with Iran, immigration with Mexico, trade with Canada, resolve questions on abortion, gay rights, and gun control, etc, etc -- than a plumber, a veterinarian, an accountant, or a mechanic?
Perhaps an attention to detail and a familiarity with logic? The number of people who can be fooled with blatant logical fallacies is amazing.
Somebody call me when computers have proved the Four Colo(u)r Theorem. Until then I'll be off playing CounterStrike (so I can work on my winning algorithm).
Ummmm, you might want to check up on the current four color theorem proof. The proof is computer generated and verified because it relies on enumerating all the possible base cases maps can be reduced to. As far as I've heard, no human has been able to directly verify every step of the proof because it is so large.
[Only God] can generate "truly" random numbers.
Oh yeah? Being omniscient, wouldn't he know what number he'd generate before he generated it? Not too random, is it?
Where does that leave my friend?
Charging for the service instead of overpriced garbage? God, are people so unimaginative that they can't imagine charging an accurate price for a real service or on the customer side actually paying someone for a service instead of a "product"? What about people who are smart enough to go spend a couple hours in the day spa and *not* buy the stupid creams? Don't they leave your friend in the exact same position?
That makes even less sense. How does the server authenticate the client? If the server just decrypts and serves up the data to any client that connects, what's the use of encrypting? And if the server requires authentication to serve up the data, it could implement access controls just as easily. That leaves you with keeping data secret from other users/the administrators/someone with a warrant. That's what per-user encryption is for.
The server authenticates clients the same way a traditional setup does, with usernames and passwords or host based authentication for NFS. I didn't say either of those were particularly good choices for secure file system access. scp would obviously be better, but isn't suited to realtime streaming. Mounting filesystems over an SSH tunnel or VPN between the client and server would work too. Per user encryption is probably better, but I don't know of many filesystems that support secure transparent user encryption, or of any that support group permissions. I haven't looked very thoroughly though, since I don't have a need for multiuser encryption.
BINGO! I've been reading the comments here wondering when the F someone was going to ask this. If someone runs off with my personal NAS then yeah I'm protected. If someone kicks in my door and logs in via a workstation or using their machine having observed my password this does NOTHING. Perhaps I could have a key secured on my workstation which is kewl but what about my XBMC'd XBOX? My aTV? My just about anything HTPCish that's like an appliance that wants to access it? Couldn't I just as easily have a PGP'd file that appears as a F/S for my workstations to send things too and leave the rest wide open and be just as secure?
Dead man switch? Alarm system? Simple menu-based security on the media PC with a reasonable timeout? All you really need is just a script that unmounts the encrypted drives if the wrong menu choice or action is made more than two or three times, or if no network activity has occurred for 30 minutes or something. If you're asking how to evade a dedicated surveillance team monitoring you with binoculars, wiretaps, keyboard loggers, and spyware, then I obviously have no idea. At that point, you might as well have encrypted your drives so that when you suspect you're being watched you can press a button to wipe the encrypted master keys from the disk within a few seconds instead of hours to wipe the data, since you'll probably be raided when you do it.
When users leave, their keys and passphrases should be deactivated so they can't use them later to gain unauthorized access. This is nontrivial because it implies that every file they've ever had the key for need to be re-encrypted with a new random key, which is a lot of processing. Practically speaking, it's better to assume that anyone who has access to the data has actually copied every available bit of plaintext and key material and plan the threat model and security around that assumption. In light of that, it may actually make sense to encrypt on both the client and the server. The server is assumed to have a key that no user knows, and the users have keys that the server doesn't know. Only collusion between a server administrator and a user would be sufficient to retrieve all the encryption keys necessary to do bulk decryption of stolen media, and only for the keys the user knows.
Key escrow is for users who forget their passwords. It also prevents the loss of data due to the loss of individuals (through firing, quiting, or death). Secret sharing can be used to ensure that n or more administrators are required to recover a key, for some n>0
Volume encryption only makes sense if there is a significant risk of losing physical control over the volume, i.e. on portable media. If your hypothetical server with private information is not in a secure datacenter, you're doing something wrong.
Unless you want to pay to have someone shred your used hard disks, encryption is really the only safe way to keep the data on them secure. If you want warranty replacement on dead disks, you'll probably have to send them back for an RMA with the data still on them if it's not encrypted.
A physically secure location also won't protect you from a warrant. If someone really needs to do something that violates a law somewhere, it would make sense to encrypt the disks so that recovery of the evidence is impossible. Hell, a media server with music and movies ripped to it might even fall under that category, depending on how angry the MAFIAA gets.
So, considering that a fileserver will have some form of access control anyway (in case of this NAS box, the locks on his house), why encrypt the entire volume in the first place? The first insecure client that connects makes the whole exercise moot, not to mention giving out the key to multiple users.
The key only exists on the server, the clients never see it. They just see a normal mount via NFS, SMB, or whatever. Yes, a client with spyware or a malicious user on it can pull all the unencrypted data. That's a risk that has to be mitigated if the data is important enough, but no more of a risk than a traditional unencrypted network server.
If, as the original poster suggests, a large number of people in your organization have to have access to the key for this to work, then it doesn't really add much security--stealing the key off someone may not be any harder than stealing the drive.
The server has a single key which uses it encrypt/decrypt the data on the disk. It sends plaintext to the users, or optionally uses some other encrypted protocol to get the data to the clients. The users don't see the hard disk key. Other access controls are needed to ensure they don't just steal all the data over their client connection.
No, you'd do all encryption and decryption on the clients. This also has the advantage of offloading all the CPU-intensive crypto to the clients. Some complexity is required to make this work for shared data, but it's possible.
Typical public key certificate setup. Define groups and users as keypairs, and encrypt each file's random symmetric cipher key with the public keys that should have access. It's harder to manage (just as hard as any certificate setup) and changing permissions requires re-encrypting the entire file, but it's probably necessary over unsecured networks with untrusted users.
That sort of thing has absolutely no basis in the federal government. Unless it was a bridge from one state or country to another, the federal government should stay the fuck away. This was an Alaskan issue that should have been dealt with and paid for by the Alaskan government. Where in the Constitution does it give the federal government the authority to construct such a bridge in just Alaska? Don't cite the state commerce clause because that is in between states, not just a single state.
As long as the Federal Government collects income tax, I expect most of that money to come back to fund state projects.
Since LUKS supports PKCS-5 style iterative hashing of the passphrase, it's a good idea to use that too. A million iterations only take a few seconds (10 on my 1.5Ghz Athlon) to compute at mount time, but make dictionary attacks a million times harder.
Seeing as that he uses per-volume encryption, this is pretty useless. It makes his 'server' pretty much a single-user NAS box, because as soon as another user gets an account to access the file server, they get access to the data.
As long as the server remains physically secure, and assuming there aren't gaping root privilege holes in the security, the files on the disk are still protected by the file system permissions. As long as the users can trust the admin, they don't have to trust each other.
Data encryption on a fileserver only makes sense if it is done on a per-user level. This is not News for Nerds, as this is basically just another implementation of how to encrypt your local disk.
Databases with private information like credit card or social security numbers should be on encrypted disks. Not to protect against users, but to protect against the drive being replaced or stolen before it can be wiped (secure wiping is not necessarily secure either, especially as drive technology advances, since what was wiped 5 years ago may be easily readable now).
There's really no advantage to having a server encrypt and decrypt each user's data with a different key. The server will have to know all the keys to perform the decryption at least (public keys allow secure encryption without the server knowing the private key), so it's only as secure as encrypting the entire drive and then relying on filesystem permissions. Root will always be able to read any files that are encrypted/decrypted on the server itself. If clients encrypt their files before storing them on the server, then the server can safely store everything in plaintext.
C) I see nowhere a calculation of the error margins. As a corolary of B, what's more interesting for such a calculation with wildly guessed numbers isn't just one value reached with the most likely guess, but what is the _interval_ of plausible results. If you've fed data which could be anything between 2% and 10%, then what is the result for 2% and what is the result for 10%, for a start. Don't give me the result just for 5%. And that's just one of the values there.
See page 25. The inverse question of which ranges of values are possible for a given optimal copyright term are examined, which as at least as much information as working forward from the assumed decay rates. Yes, you can get anywhere from 2 to 50 years because the market is incredibly dynamic. People are still buying Lord of the Rings because it's a very good book, but the pulp fiction of the 40's is probably making very little profit for its owners. Poetry from earlier in the 20th century is still popular, and the works of Shakespeare still sell pretty well too. To actually determine which decay values are appropriate would require statistical examination of the income from works over their copyrighted lifetime and some subjective estimate of value to society as a whole.
I don't see you arguing with the model, just the choice of initial values to work with. The choice was probably because the range examined includes the vast majority of current copyright periods. 95 year copyright is only a couple decades old, so there's very little empirical data. All that exists is anecdotal evidence of works that were going to enter the public domain but didn't, and very few of those works have any appreciable value now, at least not in terms of exclusive publishing rights and profits to the (probably deceased) owner of the work.
Hypertransport and PCI Express 2 have more than enough bandwidth to use it. For servers, caching content in RAM and streaming it out at 40 gb/s is not too outrageous.
That's an absurd thing to do, as, the fastest memory speed, I believe is nowhere even close to 40gb/sec and certainly no interface bus that I'm aware for PC's that can handle a network that fast. I don't even think PCI-Express is that quick, and that's only for graphics cards isn't it?
Hypertransport is supposed to be able to get over 8 GB/s (64gb/s) on some setups.
If not, you are just putting them on a fast WAN. That's great, but not the same thing as fast broadband.
P2P works just fine on fast WANs.
So, absolutely for any realistic home use, the throughput in the article is useless, since no media has currently ludicrous requirements where 4 GB of data per second can be consumed and discarded per second, and storage becomes the bottleneck for downloading. There exist applications that can benefit from transferring that much data over a network, crunching on it and being done with 4 GB datasets in a second, but they are few and far between and none really applicable for a home computer.
Spam filter?
Well, damnit, it's my cat, and all I want is credit for my own work. It's intolerable to me for others to get to take the credit, but any procedure more costly or onerous than the takedown procedure already in place would not be worth it. And the result would be that I would be disincented to create works and post them to YouTube. So much for promoting the useful arts.
Wait, you're saying that a few greedy people would prevent you from doing something altruistic just to spite them? I guess that's just human nature, but it seems incredibly irrational. If it's really that important to you, use a digital timestamping service to prove when you created it, or watermark it or something.
Oh? See, where I come from, Turing machines and the lambda calculus are formalisms for describing and computing functions, stateless mappings from a domain to a range. Operating systems, for example, are not functions, because they are not stateless.
Operating systems are functions of software, hardware and user input. This can be represented in at least two ways. The straightforward way is just to specify the interactions with hardware and the user as part of the input to a turing machine. E.g. at every step where the operating system relies on a user or external device there is enough information supplied in the input on the tape to determine the action of the turing machine. It can even be proved that the TM never needs to examine input out of order (the turing machine must process them in temporal order since it must travel linearly along the tape.), which maintains the temporal order of operations in a real operating systems. This only works for finite inputs, which is sufficient for almost any real operating system. If infinite running time must be considered then the turing machine can be made nondeterministic at the points where external input occurs in the operating system. This causes the NTM to branch nondeterministically at every step where user input occurs, and the resulting NTM follows all possible execution paths of the operating system being modeled.
This is a common theme among functional programming languages. They want to remain as purely functional as possible (because that approach has proven to be powerful), but are unable to do so in various circumstances because they have to interact with the underlying hardware or user. For instance, Haskell has its monads. Functions, as such, are unable to maintain state. They cannot express the idea of waiting for an arbitrary condition.
Only because modern computers are made that way. ENIAC and other early computers were purely functional: Plug the wires in correctly and flip the input switches, and the answer appears on the output. All microprocessors are inherently functional, they just synchronize their functional evaluations with a clock signal so that elements of some state are loaded into the inputs of a function, and during the clock cycle the outputs stabilize and are stored to some output state. All that functional programming requires to act like a modern processor is an analog of this process, which can be generalized to monads or some other serializing method with intermediate states. As far as I know, The main reason for this design is that not all functions and not all inputs and outputs can be processed as single entities. It takes a while to type a program, and it may produce pages or gigabytes of output. Imperative processors are a method of evaluating very large functions over very large values without actually having a very very large number of transistors.
That irrelevant to his point. He's not saying mathematics isn't a useful tool in computer science. He's saying that the aims of mathematicians and computer scientists are different. Even if they use the same methods. The majority of people working on whether P=NP, or extensions to Rice's theorem (there are lots), or Oracle Machines, etc. are mathematicians. These are very different kinds of problems than computer scientists are interested in. The last computer science conference I went to had papers on Data Mining, AI, computer vision and other kinds of pattern recognition, the mathematical basis of computer security, HCI, and a multitude of other subjects.
Here you have a point. Within a research field it's rarely useful to reduce the problems to basic computer theory, unless the field is brand new and needs a solid footing. However, specialization comes at the cost of generalization, and where education is concerned I prefer a general approach so that specialization can come later with the benefits of a general understanding backing it up. People do switch fields occasionally. Research into computational theory is sti
"Mathematicians and computer scientists are pursuing fundamentally different aims, and the mathematician's tools are not as appropriate as was once supposed to the questions of the computer scientist. The primary questions of computer science are not of computational possibilities but of expressional possibilities. Computer science does not need a theory of computation; it needs a comprehensive theory of process expression."
This is fundamentally, ignorantly wrong. Anyone who has worked with lambda calculus or turing machines probably has an intuitive notion of why it's wrong too. I don't know how this dude describes "expressional possibilities", but I bet he uses the notation of set theory to do so, and probably relies on the axioms of ZFC when he's talking about the possibilities, especially when he tries to count them. What does that tell you? Apparently all he wants is some different representation, but he shouldn't make sweeping remarks about mathematics being inappropriate to talk about it. Everything in science relies on mathematics. Everything in engineering relies on mathematics. Everything in computer science relies on mathematics. If it didn't, it would be magic.
A logic circuit is not a sequence of operations. An operating system is not supposed to terminate, nor does it yield a singular solution. An operating system cannot be deterministic because it must relate to uncoordinated inputs from the outside world. Any program utilising random input to carry out its process, such...is not an algorithm
Some people like the ability to shut down an operating system. If the algorithm running the operating system can't halt, then you have DOS and you just have to kill it in the middle of whatever loop it's spinning in and hope it wasn't doing anything that wasn't written to disk properly. That's not to say that working with an entire operating system in algorithmic terms is easy, I've had numerous thoughts on the best way to interpret the actions of interrupts and timing and randomness. Perhaps the best interpretation is that the operating system algorithms are actually many small halting algorithms that are directly invoked by interrupts, and the data structures are all that remains intact over the lifetime of the operating system. Most processors have a HALT instruction for just that purpose.
So your thanks is unwelcome, obviously, as I am not the inconsiderate asshole waking you up in the middle of the night as you were so quick to assume. And just as you are in your right to emit various RF signals (within reason), I am within my right to own a powerful speaker system both in my home and in my car. What I choose to do with it, and when and where I use it is what matters, and I've always understood and respected that fact.
Well, now I have the pleasure of talking to one of the few owners of a very loud stereo who doesn't abuse it. Thanks for your consideration, I only wish more people had it. Any idea which parts of said very loud stereo system are most vulnerable to RF interference? I'm thinking the amplifier circuits themselves would be the best target, because if I could introduce enough noise in the signal going into the amplifier it would either burn the speakers out or make such an incredible racket that the owner would at least turn it down. My guess is that finding good interference frequencies would mostly be a process of trial and error with each type (and brand) of amplifier circuit.
And if we were each to hit the button when we saw something un-Utopian, then it would only truly drive the possibility to zero. (I'm postulating that some things are deterministic, at least, even if their symptoms are not always.)
There's really no way to drive the probability to zero. In the worst case, the nukes just fail to kill everyone and they survive in a ruined world. In the best case, they just fail to work at all. I suppose it's a matter of degree; the closer society approached to utopia, the more likely such a disaster would be. Probably using statistics the society could estimate a reasonable level of utopia that was "safe" to run. In other words, given a probability p of the nukes failing, only choose utopian goals with probability >> p. We already play the game right now on a limited scale with MAD, as you pointed out. Only a few people have detonators, and the probability of the system wiping out humanity entirely (which isn't even a goal) is quite low. On the other hand, not everyone believes in the multiverse. Perhaps if the leaders did, we'd already have had some nuclear wars.
Quantum computing is equally bunk since it is based on the idea that a quantum property can have multiple states simultaneously, that is, when nobody is looking. ahahaha... Reminds me of the kid I knew who insisted that he could jump as high as a tall building but only when nobody was looking. Whatever happen to empiricism? Talk about pseudoscience! Everett, Schrodinger (and his stupid cat) and that lunatic David Deutsch are crackpots of the worst kinds. Only physicists can get away with such quackery. They should all be stripped naked, tarred, feathered and paraded down Fifth Avenue in New York as an example to undergraduates. ahahaha...
Sorry, your computer now refuses to work because it no longer obeys quantum mechanics. The electrons are just stuck at the N-P junctions and nothing happens because they're all in a fully defined position with no way of jumping across it at the energy levels they have. Bump the energy up, and they behave classically and just burn their way through without any of the nice semiconductor properties that make computation with them possible.
On the upside, now you'll have a lot more time to tar and feather the quacks who made your nonfunctional computer!
've observed many times that I "should have" died. It struck me that, perhaps, I did die in an alternate universe, but I (whatever I "is") continue on in at least one of the multiverses. In those multiverses in which "I" experience the death of a close friend or family member... well... that just is how it goes. But they, too, continue in an instance of the multiverse. Perhaps I do not.
Probably the most interesting practical question is what percentage of futures include all our lost family members and friends, e.g. a heaven of some kind. Obviously it's a possibility, but what is the total probability of being a consciousness somehow past death and reunited with loved ones? My guess is that at some point we will be able to understand enough about the universe to construct just about anything we want, and very likely be able to peer back into the history of the universe with arbitrary level of detail. That means that it's possible to simply reconstruct lost people from our past history at some point, with the caveat that a lot of those reconstructed people may actually only appear to be the ones we remember, as best as our memory can recall. However, to those future selves it would all appear completely logical and sane. Likewise, some simile of you and me will exist in the future universes of our friends and loved ones, and while they may not be us in the technical sense, they may be so close that "we" won't notice it while still having nearly complete memory of who we are now.