Researchers pay not only for the initial capital outlay required to install a supercomputer, but also for its power, cooling, the building it resides in, and its maintenance. This PS3 cluster might be cheap from the researchers' standpoint if they don't pay for any of these things directly, but I imagine their departments won't be real thrilled if a bunch of researchers start building their own individual "cheap" supercomputers! Those issues aside, it sounds like they're doing pretty cool stuff with those machines, so maybe more supercomputers should be cell-based!
From the full report:
"The aim of this activity is to capture the system security properties unambiguously. These security
properties are the key system properties that must hold of the system in order for it to satisfy its security
obligations.
The security properties were expressed using the Z notation; the same notation as was used for the
Formal Specification. The security properties were captured as proof obligations on the Formal
Specification, so the same level of abstraction and context was used for expression of the security
properties as was used in producing the Formal Specification.
By using the notation and context of the Formal Specification it was possible to prove that the Formal
Specification exhibits the Security Properties. The proof took the form of an informal justification, with a
discussion of the arguments required to perform each stage of the proof.
EAL5 does not demand proof of these properties, but a sample of the properties were proved to be held
by the specification, and then later by the code. At the higher levels of certification such proofs are
necessary, and can be carried out either rigorously by hand or using tool support."
It's actually not necessary to have such a powerful PC to watch standard definition TV. I built an HTPC from parts based on an Intel mini-ITX mobo (much cheaper and faster than Via), as described on my website: http://lemaymd.com/main.php?frag=gadgets-low-pc&title=Ultra-Low-Power%20Media%20PC&pfrag=gadgets It cost less than $400, consumes around 35 watts when idle, and does a great job of playing back TV. Unfortunately, I can't really recommend it for use a Linux MythTV box with its built-in graphics, because the Linux driver is horrible. I switched to XP and GB-PVR and also added a PCI nVidia 6200 and Plextor ConvertX hardware TV encoder box (they're closing them out at Newegg now for $50 apiece!). I think that we'll be seeing a lot more action in the mini-ITX space now that Intel has entered the ring.
There is a drastic difference between the idle and fully-loaded power consumption of computers these days, on the order of 2X. I think this is the biggest problem with SETI. Rather than looking for life in space, let's try to slow down the decay of our own planet.
The question of origins is much more foundational and politically relevant than the other questions mentioned in this post. A person who believes in evolution and acts accordingly will make different policy decisions than someone who believes in young-Earth Biblical creation (which is the particular belief espoused by the candidates in question). Religion shouldn't "interfere" with politics, it must direct politics if it is true religion (evolutionism is most certainly tied to various religious beliefs such as humanism and atheism, btw). A belief in evolution logically leads to a belief that humans are simply highly-advanced animals, and thus an evolutionist is more likely to support policies that treat humans like animals. Abortion, physician-assisted suicide, birth control rather than abstinence, etc. Creationists view humans as a special creation set apart from animals, so they take opposite stances. A creationist is likely to believe the rest of the Bible, so they will have different views in many other areas as well. Christians faithful to the Bible don't believe that utopia is obtainable in this lifetime, so they are less likely to even attempt it as the evolution-oriented communists did. These are just a few examples that hopefully demonstrate how pivotal this question truly is. In many ways, it is the foundation upon which all other policy decisions are supported. Basically, if you believe God created the World, then you believe He has a right to say how it should be run. If you don't, then you'll make up whatever policies seem best to you according to human logic. Unfortunately, humanism has led to the creation of governmental structures that have destroyed entire societies throughout history. No truly Biblical societies have ever been created (their very existence would contradict the principle of inherent sinfulness in the Bible), but those with the greatest Biblical influence have consistently possessed the greatest freedom and even led to the greatest advances in science, literature, music, etc. I know people will provide supposed counterexamples to that point, and it's a difficult point to prove, but just think about it yourself.
I have a power meter attached to my computer/screen combo. When I visit blackle in full-screen mode, it uses ~.5 watts less electricity than Google, and my screen consumes about 20W total.
I know you're joking on this point, but seriously please don't judge the accuracy of the museum's message from the account in this article. They were obviously visiting for the sole purpose of poking fun. I'm not speculating on that, just look at this quote discussing sibling marriage after Creation:
"Apparently there was less sin back then, and therefore fewer mutations in their DNA. Evidently sin, not two copies of the same recessive trait, gives rise to congenital birth defects."
That's absolute garbage. I've read AIG's books on genetics (e.g. One Blood), and they certainly have a solid understanding of the topic and have never made bogus statements like the one above. I'm ashamed of the Slashdot crowd for falling for baseless propaganda like this. It would get laughed out of town if it were on any other topic.
I've been running Vista x64 Business under VMware workstation (the free edition) on Fedora for months now, and it's not screaming fast, but more than fast enough for running Office 2007, etc., and far better than native XP on my old P4. I am running a Core 2 Duo with 2GB DDR2-800 and a 1066MHz FSB, though.
Good point. However, I don't have time to read all the scientific articles on the subject, so I appreciate others condensing them. Even kooks are right sometimes, and I believe the burden of proof should be on proponents of foods modified from their natural form to show that they are safe and beneficial. Perhaps that has been done, I haven't researched this extensively. It's easy enough for me to avoid this food, so I do it just in case the kooks are right. Try these searches out if you're really interested in more info:
I used to love the Boca and related products, but then I read an article about some of their bad effects: http://www.quantumbalancing.com/news/soy%20dangers .htm I still eat TVP products once every month or so, but that's about it. In fact, I strictly limit four products in my diet that I consider to be exceptionally dangerous: aspartames, MSG, hydrogenated fats, and TVP. It drives me crazy that one minute everybody's touting the benefits of some particular food, like soy, and the next minute they're saying it'll kill you, but such is the world we live in. I guess the only safe things to do are strive for variety and moderation, and attempt to eat as many minimally-processed foods as possible.
I agree. Here are some hard stats from a plain old Dell desktop that I have at my office:
Dell Dimension Celeron (P4-based) 2.4GHz Windows XP with 1GB of DDR266 RAM and 2 5400 RPM hard drives. I'm not counting the display costs, these are just for the main unit:
Completely turned off: 2.9W Standby: 5.1W Idle with hard disks spun down: 57.5W Idle: 62.5W Running a relatively busy program: 106W Peak usage during bootup: 115W
Interestingly, my new Core 2 Duo 2.13GHz Optiplex 745 with 2GB DDR2-800 and a single 250GB hard drive with integrated Intel graphics consumes just slightly more power than this, although I forget the exact stats. The Optiplex 745 is supposed to be the first of Dell's explicitly energy-conscious business PCs, and they seem to have succeeded. Notice that all these stats are quite a bit less than the "300-500 watts" quoted by the author.
I hate to be pedantic, but my Seagate 320GB 7200RPM with perpendicular recording does 73.77 MB/s. It totally destroys my last-generation Hitachi 7200RPM. This still doesn't affect your argument, of course.
In fact, stated from a conservative Christian perspective, they support the establishment of atheism as a nationally-supported religion, the slaughter of innocent children, the establishment of judges that ignore the constitution, soul-less medical research, and the complete acceptance of harmful family relationships.
This is not directly relevant, but here's an article showing that olive oil degrades into more harmful compounds when microwaved than when conventionally heated. So, thermal effects certainly aren't the only effects that ought to concern us: http://www.springerlink.com/content/0yblxvnrnhmd8p 4e/
I'm definitely going to treat my cellphone and other devices with much greater respect after this! Too bad I work in a CS building all day, no real way to escape radiation for the better part of my life.
I'm not sure what effect PatchGuard and its related technologies will actually have on security, but they certainly do cause certain hardware configurations to become unusable and confiscate a great deal of power in Microsoft's hands. I wanted to experiment with an M-Audio Delta 1010LT pro audio card on Vista 64-bit, but M-audio hasn't released any signed drivers for that particular card and has stated that they will not do so until Vista is officially shipped. Theoretically, it shouldn't have been possible for me to install the 64-bit XP drivers in their place, and it actually wasn't without some hacks. However, the necessary hacks are laid out in great detail in a public MSDN document and actually automated by some scripts in the latest Windows DDK: http://www.microsoft.com/whdc/system/platform/64bi t/kmsigning.mspx I just followed MS' tutorial on disabling driver signature enforcement and had the XP 64-bit drivers installed in about an hour, after self-signing them using automated tools. So, I'm skeptical of the strength of these new security measures. By the way, the XP drivers didn't work after all.:-)
Edison's original plan was to have a large number of small power producers distributed throughout the country, rather than a few massive producers as we have now. Putting fuel cells, solar panels, microturbines, etc. in homes and businesses is one step back towards this goal. In fact, your idea about placing fuel cells in each home is encoded in the Energy Policy Act of 2005 as a tax break for those homes that actually do this.
I concur that computers can bring a lot to this particular table.
I'm not a voting expert, but one of the most exciting possibilities to me is the chance for people to start voting their minds with respect to third parties. Currently, you're only allowed to vote for a single candidate in each race, which in a two-party system causes people to often vote for the "lesser of two evils." Once computers are responsible for counting all votes, people should be able to start saying "I really want to vote for X third party, but if X loses, I'd like to vote for Y major party instead." Running an election like this would be difficult for humans, but computers could handle the job.
Regardless, there are two high-quality voting schemes from renowned cryptographers that show some real promise for the future, even though they're not yet practical.
In "A Verifiable Secret Shuffle and its Application to E-Voting" Andrew Neff describes a protocol "to verifiably shuffle a sequence of k modular integers" to represent a ballot. He relates the protocol to the problem of achieving a random, yet verifiable permutation of some input sequence, like a card player who has verified the composition of a deck of cards before they are shuffled, and yet doesn't know the ordering of the cards after they've been shuffled. Normally, the auditor must be able to see all of the input values during the audit, but in an election this is obviously undesirable (because then the auditor [vote buyer] knows how the affected individual voted). Of course, I can't present all the details here, but the basic principle of the system is that there are a number of rows each containing a fixed number of pairs of 1-bit El-Gamal ciphertexts. Each row represents a candidate. In the row representing the candidate that the voter selected, each pair of encrypted numbers is homogeneous, they are 0-0 or 1-1. In the other rows, the numbers are heterogeneous: 0-1 or 1-0. Of course, the encryption obscures these relationships in the machine's output. So, how does the voter know that the proper vote was cast by this black box? For each pair of bits in the row corresponding to the chosen candidate, the machine produces a pledge bit that specifies whether that pair of bits is 0-0 or 1-1. After the machine has printed the receipt with the ciphertexts, the voter dictates to the machine whether to expose the randomness for the left or right bit in each pair. Since the bits are supposed to be the same, it shouldn't matter which side is opened. However, if the machine cheated, and the pairs in that row are heterogeneous, then there is an exponentially decreasing probability that the voter will not choose the side that corresponds to the value the machine committed to for that pair. This complicated scheme of ciphertexts and challenges is necessary to prevent vote buying, see the paper for all the details.
Another scheme was devised by David Chaum in "Secret-Ballot Receipts: True Voter-Verifiable Elections." This scheme uses double-layer transparent receipts that use "visual encryption" to encode a voter's choice on a ballot by printing specially-organized checkerboard patterns that overlap to form big letters visible to the voter. However, when the voter leaves the booth, they separate the two layers and only keep one as a receipt. Both layers look completely random when separated, so they again are resistant to coercion and vote-buying. There's some heavy crypto at work in this scheme, too, so you'll have to read the paper for full details.
Both of these schemes post all of the ballots to a public bulletin board so that voters can verify from home that their votes were counted-as-cast. However, they still have some flaws, most of which stem from human factors (humans aren't very dependable participants in cryptographic protocols). They also introduce some potential subliminal channels that could be used for voter coercion, since ballots are posted in a modified form to a public bulletin board. A full analysis of those problems is pre
I'd be glad to test a patch; I should be able to recompile the kernel and revert to a standard myth installation with little difficulty. You can send it to lemaymd @t lemaymd d.t com. Thanks!
I wasn't even able to build v4lctl on FC5, unfortunately. Otherwise that would have allowed me to use the standard RPMs, which would be much easier to maintain and upgrade. I'd be willing to try switching back to standard Myth and hack something into my kernel if you have a rough idea of where the problem occurs. I spent 45 minutes this morning playing around with strace and watching the output of the module with video_debug on, but I still don't see where the unmute operation should properly be occurring. I see that the module ignores the V4L1 calls VIDIOCMCAPTURE and VIDIOCSYNC, but those don't seem to unmute the card in the other, presumably well-formed modules. Furthermore, I've discovered at least one other bug in the saa7134 module, and I reported it to the maintainer some time ago in proper patch format (I've successfully submitted patches before), but he never responded. That kind of discourages me from looking much harder, since my work will probably get ignored anyway.
Well, maybe there's just some quirk with my system, but the audio doesn't unmute when I change channels or start a recording. It's apparently a problem for a number of people, as someone had posted a patch to fix the problem by manually invoking a V4L ioctl to unmute the card when necessary.
I'm using the July 8th snapshot on Linux version 2.6.18-rc4 (gcc version 4.1.1 20060525 (Red Hat 4.1.1-1)) #1 SMP, which includes the new ALSA interface to SAA7134 sound. The problem is actually in the SAA7134 ALSA driver, not Myth itself, and Myth probably works just fine if you're using the older OSS interface.
Slashdot Mirror
Ah, that is a cool feature! That is the most amazing-looking clock I've ever seen, btw. Nice work!
It's funny that in a clock centered on a massive vacuum tube they highlight their low-power RTC! Amdahl's law...
Researchers pay not only for the initial capital outlay required to install a supercomputer, but also for its power, cooling, the building it resides in, and its maintenance. This PS3 cluster might be cheap from the researchers' standpoint if they don't pay for any of these things directly, but I imagine their departments won't be real thrilled if a bunch of researchers start building their own individual "cheap" supercomputers! Those issues aside, it sounds like they're doing pretty cool stuff with those machines, so maybe more supercomputers should be cell-based!
From the full report: "The aim of this activity is to capture the system security properties unambiguously. These security properties are the key system properties that must hold of the system in order for it to satisfy its security obligations. The security properties were expressed using the Z notation; the same notation as was used for the Formal Specification. The security properties were captured as proof obligations on the Formal Specification, so the same level of abstraction and context was used for expression of the security properties as was used in producing the Formal Specification. By using the notation and context of the Formal Specification it was possible to prove that the Formal Specification exhibits the Security Properties. The proof took the form of an informal justification, with a discussion of the arguments required to perform each stage of the proof. EAL5 does not demand proof of these properties, but a sample of the properties were proved to be held by the specification, and then later by the code. At the higher levels of certification such proofs are necessary, and can be carried out either rigorously by hand or using tool support."
It's actually not necessary to have such a powerful PC to watch standard definition TV. I built an HTPC from parts based on an Intel mini-ITX mobo (much cheaper and faster than Via), as described on my website: http://lemaymd.com/main.php?frag=gadgets-low-pc&title=Ultra-Low-Power%20Media%20PC&pfrag=gadgets It cost less than $400, consumes around 35 watts when idle, and does a great job of playing back TV. Unfortunately, I can't really recommend it for use a Linux MythTV box with its built-in graphics, because the Linux driver is horrible. I switched to XP and GB-PVR and also added a PCI nVidia 6200 and Plextor ConvertX hardware TV encoder box (they're closing them out at Newegg now for $50 apiece!). I think that we'll be seeing a lot more action in the mini-ITX space now that Intel has entered the ring.
Well, we should be able to improve on paper ballots by permitting people to audit their own ballots, as in the schemes designed by Chaum and Neff.
There is a drastic difference between the idle and fully-loaded power consumption of computers these days, on the order of 2X. I think this is the biggest problem with SETI. Rather than looking for life in space, let's try to slow down the decay of our own planet.
The question of origins is much more foundational and politically relevant than the other questions mentioned in this post. A person who believes in evolution and acts accordingly will make different policy decisions than someone who believes in young-Earth Biblical creation (which is the particular belief espoused by the candidates in question). Religion shouldn't "interfere" with politics, it must direct politics if it is true religion (evolutionism is most certainly tied to various religious beliefs such as humanism and atheism, btw). A belief in evolution logically leads to a belief that humans are simply highly-advanced animals, and thus an evolutionist is more likely to support policies that treat humans like animals. Abortion, physician-assisted suicide, birth control rather than abstinence, etc. Creationists view humans as a special creation set apart from animals, so they take opposite stances. A creationist is likely to believe the rest of the Bible, so they will have different views in many other areas as well. Christians faithful to the Bible don't believe that utopia is obtainable in this lifetime, so they are less likely to even attempt it as the evolution-oriented communists did. These are just a few examples that hopefully demonstrate how pivotal this question truly is. In many ways, it is the foundation upon which all other policy decisions are supported. Basically, if you believe God created the World, then you believe He has a right to say how it should be run. If you don't, then you'll make up whatever policies seem best to you according to human logic. Unfortunately, humanism has led to the creation of governmental structures that have destroyed entire societies throughout history. No truly Biblical societies have ever been created (their very existence would contradict the principle of inherent sinfulness in the Bible), but those with the greatest Biblical influence have consistently possessed the greatest freedom and even led to the greatest advances in science, literature, music, etc. I know people will provide supposed counterexamples to that point, and it's a difficult point to prove, but just think about it yourself.
I have a power meter attached to my computer/screen combo. When I visit blackle in full-screen mode, it uses ~.5 watts less electricity than Google, and my screen consumes about 20W total.
I know you're joking on this point, but seriously please don't judge the accuracy of the museum's message from the account in this article. They were obviously visiting for the sole purpose of poking fun. I'm not speculating on that, just look at this quote discussing sibling marriage after Creation:
"Apparently there was less sin back then, and therefore fewer mutations in their DNA. Evidently sin, not two copies of the same recessive trait, gives rise to congenital birth defects."
That's absolute garbage. I've read AIG's books on genetics (e.g. One Blood), and they certainly have a solid understanding of the topic and have never made bogus statements like the one above. I'm ashamed of the Slashdot crowd for falling for baseless propaganda like this. It would get laughed out of town if it were on any other topic.
I've been running Vista x64 Business under VMware workstation (the free edition) on Fedora for months now, and it's not screaming fast, but more than fast enough for running Office 2007, etc., and far better than native XP on my old P4. I am running a Core 2 Duo with 2GB DDR2-800 and a 1066MHz FSB, though.
Good point. However, I don't have time to read all the scientific articles on the subject, so I appreciate others condensing them. Even kooks are right sometimes, and I believe the burden of proof should be on proponents of foods modified from their natural form to show that they are safe and beneficial. Perhaps that has been done, I haven't researched this extensively. It's easy enough for me to avoid this food, so I do it just in case the kooks are right. Try these searches out if you're really interested in more info:
t rogenic+soybean+flour&btnG=Search+ phytic+acid&btnG=Search
- http://scholar.google.com/scholar?hl=en&lr=&q=goi
- http://scholar.google.com/scholar?hl=en&lr=&q=soy
I used to love the Boca and related products, but then I read an article about some of their bad effects: http://www.quantumbalancing.com/news/soy%20dangers .htm I still eat TVP products once every month or so, but that's about it. In fact, I strictly limit four products in my diet that I consider to be exceptionally dangerous: aspartames, MSG, hydrogenated fats, and TVP. It drives me crazy that one minute everybody's touting the benefits of some particular food, like soy, and the next minute they're saying it'll kill you, but such is the world we live in. I guess the only safe things to do are strive for variety and moderation, and attempt to eat as many minimally-processed foods as possible.
I agree. Here are some hard stats from a plain old Dell desktop that I have at my office:
Dell Dimension Celeron (P4-based) 2.4GHz Windows XP with 1GB of DDR266 RAM and 2 5400 RPM hard drives. I'm not counting the display costs, these are just for the main unit:
Completely turned off: 2.9W
Standby: 5.1W
Idle with hard disks spun down: 57.5W
Idle: 62.5W
Running a relatively busy program: 106W
Peak usage during bootup: 115W
Interestingly, my new Core 2 Duo 2.13GHz Optiplex 745 with 2GB DDR2-800 and a single 250GB hard drive with integrated Intel graphics consumes just slightly more power than this, although I forget the exact stats. The Optiplex 745 is supposed to be the first of Dell's explicitly energy-conscious business PCs, and they seem to have succeeded. Notice that all these stats are quite a bit less than the "300-500 watts" quoted by the author.
I hate to be pedantic, but my Seagate 320GB 7200RPM with perpendicular recording does 73.77 MB/s. It totally destroys my last-generation Hitachi 7200RPM. This still doesn't affect your argument, of course.
The attributes you ascribe to progressive Christians characterize all true Christians obedient to the Bible.
o G/b.593939/k.A10D/Values_Statement.htm#least_of_th ese and here: http://www.christianalliance.org/site/c.bnKIIQNtEo G/b.593939/k.A10D/Values_Statement.htm#least_of_th ese
h tm
The actual progressive groups cited in this article list their values here: http://www.christianalliance.org/site/c.bnKIIQNtE
In fact, stated from a conservative Christian perspective, they support the establishment of atheism as a nationally-supported religion, the slaughter of innocent children, the establishment of judges that ignore the constitution, soul-less medical research, and the complete acceptance of harmful family relationships.
I personally don't like this game. However, others might want to make up their own minds after reading the company's response to the controversy: http://www.leftbehindgames.com/pages/controversy.
If I were a contestant, I would make sure my vehicle stays out of the way of Oshkosh Truck's entry! http://www.darpa.mil/grandchallenge/Teams/Track_A_ Teams/TeamOshkoshTruck.asp
Citation?
What about this article showing that subthermal 2.4GHz microwaves significantly accelerated the development of chemically-induced cancer?: http://www.springerlink.com/content/gl78h815206128 71/
Here's a processed version of a Lancet article stating some really scary things: http://www.2lolii.com/If%20Mobile%20Phones%20Were% 20a%20Type%20of%20Food.pdf. Apparently cellphones happen to resonate with important brain waves.
This is not directly relevant, but here's an article showing that olive oil degrades into more harmful compounds when microwaved than when conventionally heated. So, thermal effects certainly aren't the only effects that ought to concern us: http://www.springerlink.com/content/0yblxvnrnhmd8p 4e/
I'm definitely going to treat my cellphone and other devices with much greater respect after this! Too bad I work in a CS building all day, no real way to escape radiation for the better part of my life.
I'm not sure what effect PatchGuard and its related technologies will actually have on security, but they certainly do cause certain hardware configurations to become unusable and confiscate a great deal of power in Microsoft's hands. I wanted to experiment with an M-Audio Delta 1010LT pro audio card on Vista 64-bit, but M-audio hasn't released any signed drivers for that particular card and has stated that they will not do so until Vista is officially shipped. Theoretically, it shouldn't have been possible for me to install the 64-bit XP drivers in their place, and it actually wasn't without some hacks. However, the necessary hacks are laid out in great detail in a public MSDN document and actually automated by some scripts in the latest Windows DDK: http://www.microsoft.com/whdc/system/platform/64bi t/kmsigning.mspx I just followed MS' tutorial on disabling driver signature enforcement and had the XP 64-bit drivers installed in about an hour, after self-signing them using automated tools. So, I'm skeptical of the strength of these new security measures. By the way, the XP drivers didn't work after all. :-)
Edison's original plan was to have a large number of small power producers distributed throughout the country, rather than a few massive producers as we have now. Putting fuel cells, solar panels, microturbines, etc. in homes and businesses is one step back towards this goal. In fact, your idea about placing fuel cells in each home is encoded in the Energy Policy Act of 2005 as a tax break for those homes that actually do this.
I concur that computers can bring a lot to this particular table.
I'm not a voting expert, but one of the most exciting possibilities to me is the chance for people to start voting their minds with respect to third parties. Currently, you're only allowed to vote for a single candidate in each race, which in a two-party system causes people to often vote for the "lesser of two evils." Once computers are responsible for counting all votes, people should be able to start saying "I really want to vote for X third party, but if X loses, I'd like to vote for Y major party instead." Running an election like this would be difficult for humans, but computers could handle the job.
Regardless, there are two high-quality voting schemes from renowned cryptographers that show some real promise for the future, even though they're not yet practical.
In "A Verifiable Secret Shuffle and its Application to E-Voting" Andrew Neff describes a protocol "to verifiably shuffle a sequence of k modular integers" to represent a ballot. He relates the protocol to the problem of achieving a random, yet verifiable permutation of some input sequence, like a card player who has verified the composition of a deck of cards before they are shuffled, and yet doesn't know the ordering of the cards after they've been shuffled. Normally, the auditor must be able to see all of the input values during the audit, but in an election this is obviously undesirable (because then the auditor [vote buyer] knows how the affected individual voted). Of course, I can't present all the details here, but the basic principle of the system is that there are a number of rows each containing a fixed number of pairs of 1-bit El-Gamal ciphertexts. Each row represents a candidate. In the row representing the candidate that the voter selected, each pair of encrypted numbers is homogeneous, they are 0-0 or 1-1. In the other rows, the numbers are heterogeneous: 0-1 or 1-0. Of course, the encryption obscures these relationships in the machine's output. So, how does the voter know that the proper vote was cast by this black box? For each pair of bits in the row corresponding to the chosen candidate, the machine produces a pledge bit that specifies whether that pair of bits is 0-0 or 1-1. After the machine has printed the receipt with the ciphertexts, the voter dictates to the machine whether to expose the randomness for the left or right bit in each pair. Since the bits are supposed to be the same, it shouldn't matter which side is opened. However, if the machine cheated, and the pairs in that row are heterogeneous, then there is an exponentially decreasing probability that the voter will not choose the side that corresponds to the value the machine committed to for that pair. This complicated scheme of ciphertexts and challenges is necessary to prevent vote buying, see the paper for all the details.
Another scheme was devised by David Chaum in "Secret-Ballot Receipts: True Voter-Verifiable Elections." This scheme uses double-layer transparent receipts that use "visual encryption" to encode a voter's choice on a ballot by printing specially-organized checkerboard patterns that overlap to form big letters visible to the voter. However, when the voter leaves the booth, they separate the two layers and only keep one as a receipt. Both layers look completely random when separated, so they again are resistant to coercion and vote-buying. There's some heavy crypto at work in this scheme, too, so you'll have to read the paper for full details.
Both of these schemes post all of the ballots to a public bulletin board so that voters can verify from home that their votes were counted-as-cast. However, they still have some flaws, most of which stem from human factors (humans aren't very dependable participants in cryptographic protocols). They also introduce some potential subliminal channels that could be used for voter coercion, since ballots are posted in a modified form to a public bulletin board. A full analysis of those problems is pre
I'd be glad to test a patch; I should be able to recompile the kernel and revert to a standard myth installation with little difficulty. You can send it to lemaymd @t lemaymd d.t com. Thanks!
I wasn't even able to build v4lctl on FC5, unfortunately. Otherwise that would have allowed me to use the standard RPMs, which would be much easier to maintain and upgrade. I'd be willing to try switching back to standard Myth and hack something into my kernel if you have a rough idea of where the problem occurs. I spent 45 minutes this morning playing around with strace and watching the output of the module with video_debug on, but I still don't see where the unmute operation should properly be occurring. I see that the module ignores the V4L1 calls VIDIOCMCAPTURE and VIDIOCSYNC, but those don't seem to unmute the card in the other, presumably well-formed modules. Furthermore, I've discovered at least one other bug in the saa7134 module, and I reported it to the maintainer some time ago in proper patch format (I've successfully submitted patches before), but he never responded. That kind of discourages me from looking much harder, since my work will probably get ignored anyway.
Well, maybe there's just some quirk with my system, but the audio doesn't unmute when I change channels or start a recording. It's apparently a problem for a number of people, as someone had posted a patch to fix the problem by manually invoking a V4L ioctl to unmute the card when necessary.
I'm using the July 8th snapshot on Linux version 2.6.18-rc4 (gcc version 4.1.1 20060525 (Red Hat 4.1.1-1)) #1 SMP, which includes the new ALSA interface to SAA7134 sound. The problem is actually in the SAA7134 ALSA driver, not Myth itself, and Myth probably works just fine if you're using the older OSS interface.